Polymeric materials formed using initiators with two thiocarbonylthio-containing groups

ABSTRACT

Controlled radical initiators, reaction mixtures containing the controlled radical initiators and various ethylenically unsaturated monomers, polymeric materials formed from the reaction mixtures, crosslinkable compositions containing the polymeric materials, crosslinked compositions formed from the crosslinkable compositions, and articles containing the polymeric materials, the crosslinkable compositions, or the crosslinked compositions are provided. The controlled radical initiators are bis-dithiocarbamate or bis-dithiocarbonate compounds having a single carbon between the two dithiocarbamate or dithiocarbonate groups. Also attached to that single carbon is a ketone group.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication No. 62/607,499, filed Dec. 19, 2017, the disclosure of whichis incorporated by reference herein in its entirety.

TECHNICAL FIELD

Controlled radical initiators and polymeric materials formed usingcontrolled radical initiators are provided.

BACKGROUND

The performance characteristics of polymeric materials are determinednot only by their composition but also by their molecular architecture.For copolymers, various properties such as melt viscosity, glasstransition temperature, and modulus are often a function of thedistribution of the different monomeric units along the polymeric chain.Conventional radical polymerization methods have limited utility insynthesizing polymers with precise architectural and structuralcharacteristics.

Controlled radical polymerization methods have been developed that allowthe preparation of polymers with well-defined molecular weight,polydispersity, topology, composition, and microstructure. These methodsare based on the use of special polymerization mediators, whichtemporarily and reversibly transform propagating radicals into dormantand/or stable species. These reversible transformations are typicallyeither accomplished by reversible deactivation or by reversible chaintransfer. Some of the methods that involve controlled radicalpolymerization through reversible transformations include inifertermethods, nitroxide mediated polymerization (NMP) methods, atom transferpolymerization (ATRP) methods, and reversible addition-fragmentation(RAFT) methods.

The terms “iniferter” and “photoiniferters” refer to molecules that canact as an initiator, chain transfer agent, and terminator. Variousiniferters were discussed in Otsu et al., Makromol. Chem., RapidCommun., 3, 127-132 (1982). The compound p-xylenebis(N,N-diethyldithiocarbamate) (XDC) has been used to form variousacrylic-based block copolymers such as those described in EuropeanPatent Applications 0286376 A2 (Otsu et al.) and 0349270 A2 (Mahfuza etal.).

Some polymeric materials have been formed by applying a layer of acrosslinkable composition to the surface of a substrate. Thecrosslinkable composition can contain a pre-polymer plus additionalmonomers and a crosslinking agent. Crosslinked compositions can beprepared by exposing the crosslinkable composition to actinic radiationsuch as ultraviolet radiation. Such polymeric materials and processesare described in U.S. Pat. No. 4,181,752 (Martens et al.), U.S. Pat. No.4,330,590 (Vesley), U.S. Pat. No. 4,329,384 (Vesley et al.), U.S. Pat.No. 4,379,201 (Heilmann et al.), U.S. Pat. No. 5,506,279 (Babu et al.),U.S. Pat. No. 5,773,836 (Bennett et al.), and U.S. Pat. No. 5,773,485(Bennett et al.).

SUMMARY

Controlled radical initiators, reaction mixtures containing thecontrolled radical initiators and various ethylenically unsaturatedmonomers, polymeric materials formed from the reaction mixtures,crosslinkable compositions containing the polymeric materials,crosslinked compositions formed from the crosslinkable compositions, andarticles containing the polymeric materials, the crosslinkablecompositions, or the crosslinked compositions are provided. Thecontrolled radical initiators are bis-dithiocarbamate orbis-dithiocarbonate compounds having a single carbon between the twodithiocarbamate or dithiocarbonate groups. Also attached to that singlecarbon is a ketone group.

In a first aspect, a first reaction mixture is provided. The firstreaction mixture includes a) a photoinitiator of Formula (I)

and b) a first monomer composition containing at least one monomerhaving a single ethylenically unsaturated group. In Formula (I), groupR¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂. Group R² is alkyl,aryl, aralkyl, or substituted aryl, wherein the substituted aryl is anaryl substituted with at least one alkyl, alkoxy, halo, or a combinationthereof. Each R³ is an alkyl or two adjacent R³ groups are combined withthe nitrogen to which they are both attached to form a firstheterocyclic ring having 1 to 3 heteroatoms selected from nitrogen,oxygen, and sulfur, the first heterocyclic ring being saturated orunsaturated and optionally fused to one or more second rings that arecarbocyclic or heterocyclic.

In a second aspect, a polymeric material of Formula (II) is provided.

In Formula (II), group R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂.Group R² is alkyl, aryl, aralkyl, or substituted aryl, wherein thesubstituted aryl is an aryl substituted with at least one alkyl, alkoxy,halo, or a combination thereof. Each R³ is an alkyl or two adjacent R³groups are combined with the nitrogen to which they are both attached toform a first heterocyclic ring having 1 to 3 heteroatoms selected fromnitrogen, oxygen, and sulfur, the first heterocyclic ring beingsaturated or unsaturated and optionally fused to one or more secondrings that are carbocyclic or heterocyclic. Each P is a polymeric blockthat comprises a polymerized product of a first monomer compositioncomprising at least one monomer having a single ethylenicallyunsaturated group. The variables y and z refer to the number ofpolymeric blocks. The variable y is an integer in a range of 1 to 10,and the variable z is an integer in a range of 0 to y.

In a third aspect, a crosslinkable composition is provided that containsa) a polymeric material of Formula (II) as described above in the secondaspect and b) a second monomer composition comprising a crosslinkingmonomer having at least two ethylenically unsaturated groups.

In a fourth aspect, a crosslinked composition is provided. Thecrosslinked composition includes a cured product of a crosslinkablecomposition. The crosslinkable composition is the same as describedabove in the third aspect.

In a fifth aspect, an article is provided that includes a firstsubstrate and a polymeric material layer positioned adjacent to thefirst substrate. The polymeric material is of Formula (II) as describedabove in the second aspect.

In a sixth aspect, an article is provided that includes a firstsubstrate and a crosslinkable composition layer adjacent to the firstsubstrate. The crosslinkable composition layer contains thecrosslinkable composition described above in the third aspect.

In a seventh aspect, another article is provided that includes a firstsubstrate and a crosslinked composition layer adjacent to the firstsubstrate. The crosslinked composition layer contains the crosslinkedcomposition described above in the fourth aspect.

In an eighth aspect, a compound is provided. The compound is of Formula(I-B) and can function as a photoinitiator.

In Formula (I-B), group R² is alkyl, aryl, aralkyl, or substituted aryl,wherein the substituted aryl is an aryl substituted with at least onealkyl, alkoxy, halo, or combination thereof. Each R³ is an alkyl or twoadjacent R³ groups are combined with the nitrogen to which they are bothattached to form a first heterocyclic ring having 1 to 3 heteroatomsselected from nitrogen, oxygen, and sulfur, the first heterocyclic ringbeing saturated or unsaturated and optionally fused to one or moresecond rings that are carbocyclic or heterocyclic.

In a ninth aspect, a compound is provided. The compound is of Formula(I-C) and can function as a photoinitiator.

In Formula (I-C), group —OR¹⁰ is an alkoxy, aralkyloxy, or alkenoxy.Group R²⁰ is an alkyl.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 shows the aromatic region of the ¹H NMR spectrum for Example 11after 6 percent conversion (i.e., polymerization) of the monomer.

DETAILED DESCRIPTION

Controlled radical initiators, reaction mixtures containing thecontrolled radical initiators and various ethylenically unsaturatedmonomers, polymeric materials formed from the reaction mixtures,crosslinkable compositions containing the polymeric materials,crosslinked compositions formed from the crosslinkable compositions, andvarious articles are provided. The controlled radical initiators arebis-dithiocarbamate or bis-dithiocarbonate compounds having a singlecarbon between the two dithiocarbamate or dithiocarbonate groups. Alsoattached to that single carbon is a ketone group.

The controlled radical initiator compounds can be referred to asiniferters because they can function as a controlled radical initiator,transfer agent, and terminator. The controlled radical initiators can bereferred to as photoinitiators or photoiniferters because the controlledradical polymerization reaction typically is photolytically induced. Theresulting polymeric material formed from the controlled radicalinitiators have terminal dithiocarbamate or dithiocarbonate groups.

The polymeric materials having well controlled architectures can beformed using these photoinitiator compounds. The polymeric materials canbe homopolymers, random copolymers, or block copolymers. Crosslinkablecompositions can be prepared that contain the polymeric materials and amonomer composition that includes a crosslinking monomer having at leasttwo ethylenically unsaturated groups. When the crosslinkable compositionis exposed to actinic radiation (e.g., ultraviolet region of theelectromagnetic spectrum), the polymeric material undergoes chainextension and crosslinking reactions.

The terms “a”, “an”, and “the” are used interchangeably with “at leastone” to mean one or more of the elements being described.

The term “and/or” means either or both. For example, “A and/or B” meansonly A, only B, or both A and B.

The terms “polymer” and “polymeric material” are used interchangeablyand refer to materials formed by reacting one or more monomers. Theterms include homopolymers, copolymers, terpolymers, or the like.Likewise, the terms “polymerize” and “polymerizing” refer to the processof making a polymeric material that can be a homopolymer, copolymer,terpolymer, or the like.

The term “alkyl” refers to a monovalent group that is a radical of analkane. The alkyl group can have 1 to 32 carbon atoms, 1 to 20 carbonatoms, 1 to 12 carbon atoms, or 1 to 6 carbon atoms. The alkyl can belinear, branched, cyclic, or a combination thereof. A linear alkyl hasat least one carbon atoms while a cyclic or branched alkyl has at least3 carbon atoms. In some embodiments, if there are greater than 12 carbonatoms, the alkyl is branched.

The term “alkoxy” refers to a monovalent group of formula —OW where W isan alkyl as defined above.

The term “alkylene” refers to a divalent group that is a radical of analkane. The alkylene group can have 1 to 32 carbon atoms, 1 to 20 carbonatoms, 1 to 12 carbon atoms, or 1 to 6 carbon atoms. The alkylene can belinear, branched, cyclic, or a combination thereof. A linear alkylenehas at least one carbon atoms while a cyclic or branched alkylene has atleast 3 carbon atoms. In some embodiments, if there are greater than 12carbon atoms, the alkyl is branched.

The term “aryl” refers to a monovalent group that is a radical of anaromatic carbocyclic compound. The aryl group has at least one aromaticcarbocyclic ring and can have 1 to 5 optional rings that are connectedto or fused to the aromatic carbocyclic ring. The additional rings canbe aromatic, aliphatic, or a combination thereof. The aryl group usuallyhas 5 to 20 carbon atoms or 6 to 10 carbon atoms.

The term “substituted aryl” refers to an aryl group substituted with atleast one alkyl, alkoxy, halo, or combination thereof. The aryl is thesame as defined above. The alkyl and alkoxy groups are the same asdefined above and the halo is selected from chloro, bromo, iodo, orfluoro. As used in defining substituted aryl, the term “combination”means that the aryl can be substituted with multiple different types ofsubstituent groups. Alternatively, the term combination means the arylcan be substituted with an alkyl or alkoxy that is further substitutedwith a halo.

The term “aryloxy” refers to a monovalent group that is of formula —O—Arwhere Ar is an aryl group as defined above.

The term “aralkyl” refers to an alkyl group substituted with at leastone aryl group. That is, the aralkyl group is of formula —R^(d)—Ar whereR^(d) is an alkylene and Ar is an aryl. The aralkyl group contains 6 to40 carbon atoms. The aralkyl group often contains an alkylene grouphaving 1 to 20 carbon atoms or 1 to 10 carbon atoms and an aryl grouphaving 5 to 20 carbon atoms or 6 to 10 carbon atoms.

The term “aralkyloxy” refers to a monovalent group of formula—O—R^(d)—Ar where R^(d) and Ar are defined above for an aralkyl.

The term “alkenyl” refers to a monovalent group that is a radical of analkene, which is a compound having at least one carbon-carbon doublebond. In some embodiments, the alkenyl has a single carbon-carbon doublebond. In some more specific embodiments, the alkenyl has a terminalethylenically unsaturated group. The alkenyl can be linear, branched, orcyclic. The alkenyl has 2 to 20 carbon atoms, 2 to 10 carbon atoms, or 2to 6 carbon atoms.

The term “alkenyloxy” refers to a monovalent group of formula —OR^(b)where R^(b) is an alkenyl as defined above.

The term “heteroalkyl” refers to an alkyl group where at least one ofthe catenated carbon atoms is replaced with oxy, thio, or —NH—.

The term “heterocyclic ring” refers to a ring structure having at least1 heteroatom selected from oxygen, nitrogen, or sulfur, wherein the ringstructure is saturated or unsaturated. The heterocyclic ring typicallyhas 5 to 7 ring atoms and 1 to 3 heteroatoms. The heterocyclic ring canoptionally be fused to one or more additional rings that are carbocyclicor heterocyclic and that can be saturated or unsaturated. Any of therings can optionally be substituted with an alkyl group.

The term “ketone group” refers to a group —(CO)—R² where R² is an alkyl,aryl, aralkyl, or substituted aryl.

The term “(meth)acryloyl” refers to a group of formula CH₂═CHR^(c)—(CO)—where RC is hydrogen or methyl and the group —(CO)— refers to a carbonylgroup.

The term “(meth)acrylate” refers to an acrylate, a methacrylate, orboth. Likewise, the term “(meth)acrylamide” refers to an acrylamide, amethacrylamide, or both and the term “(meth)acrylic acid” refers toacrylic acid, methacrylic acid, or both.

The terms “in a range of” or “in the range of” are used interchangeablyto refer to all values within the range plus the endpoints of the range.

Various reaction mixtures and polymeric materials are provided using aphotoinitiator of Formula (I).

More particularly, polymeric materials are formed from a reactionmixture that includes both (a) a photoinitiator of Formula (I) and (b) amonomer composition containing at least one monomer having a singleethylenically unsaturated group. Upon exposure to actinic radiation inthe ultraviolet region of the electromagnetic spectrum, a polymerizationreaction commences.

In Formula (I), group R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂.Group R² is alkyl, aryl, aralkyl, or substituted aryl, wherein thesubstituted aryl is an aryl substituted with at least one alkyl, alkoxy,halo, or combination thereof. Each R³ is an alkyl or two adjacent R³groups are combined with the nitrogen to which they are both attached toform a first heterocyclic ring having 1 to 3 heteroatoms selected fromnitrogen, oxygen, and sulfur, the first heterocyclic ring beingsaturated or unsaturated and optionally fused to one or more secondrings that are carbocyclic or heterocyclic.

In some embodiments of Formulas (I), each R¹ is an alkoxy, aralkyloxy,or alkenoxy. Such photoinitiators are of Formula (I-A) where —OR¹⁰ is analkyloxy, aralkyloxy, or alkenoxy (i.e., R¹⁰ is an alkyl, aralkyl, oralkenyl).

These photoinitiators are bis-dithiocarbonate compounds having a singlecarbon atom between the two dithiocarbonate groups.

Suitable alkoxy groups for R′ of Formula (I) and for —OR¹⁰ of Formula(I-A) typically have at least 1 carbon atom, at least 2 carbon atoms, atleast 3 carbon atoms, or at least 4 carbon atoms and can have up to 20carbon atoms, up to 18 carbon atoms, up to 16 carbon atoms, up to 12carbon atoms, or up to 10 carbon atoms. Some example alkoxy groups have1 to 20 carbon atoms, 1 to 10 carbon atoms, 2 to 10 carbon atoms, 1 to 6carbon atoms, 2 to 6 carbon atoms, or 1 to 4 carbon atoms. Suitablearalkyloxy groups for R¹ and for —OR¹⁰ typically contains an alkylenegroup having 1 to 10 carbon atoms, 1 to 6 carbon atoms, or 1 to 4 carbonatoms and an aryl group having 5 to 12 carbon atoms, 6 to 12 carbonatoms, or 6 to 10 carbon atoms. The aryl group in the aralkyloxy groupis often phenyl. Suitable alkenoxy groups for R¹ and for —OR¹⁰ typicallyhave at least 2 carbon atoms, at least 3 carbon atoms, or at least 4carbon atoms and can have up to 20 carbon atoms, up to 18 carbon atoms,up to 16 carbon atoms, up to 12 carbon atoms, up to 10 carbon atoms, orup to 6 carbons. Some example alkenoxy groups have 2 to 20 carbon atoms,2 to 10 carbon atoms, 2 to 8 carbon atoms, 2 to 6 carbon atoms, or 2 to4 carbon atoms. In many embodiments R¹⁰ in Formula (I-A) is an alkyl(i.e., group —OR′° is an alkoxy in Formula (I-A) corresponds to group R¹is an alkoxy in Formula (I)).

Some more specific photoinitiators of Formula (I-A) are of Formula(I-C).

In Formula (I-C), group —OR¹⁰ is an alkyloxy, aralkyloxy, or alkenoxy(i.e., R¹⁰ is an alkyl, aralkyl, or alkenyl). Suitable alkoxy,aralkyloxy, and alkenoxy groups are the same as described above forFormulas (I) and (I-A). Group R²⁰ is an alkyl. Suitable alkyl groups forR²⁰ typically have at least 1 carbon atom, at least 2 carbon atoms, atleast 3 carbon atoms, or at least 4 carbon atoms and can have up to 20carbon atoms, up to 18 carbon atoms, up to 16 carbon atoms, up to 12carbon atoms, or up to 10 carbon atoms. Some example alkyl groups have 1to 20 carbon atoms, 1 to 10 carbon atoms, 2 to 10 carbon atoms, 1 to 6carbon atoms, 2 to 6 carbon atoms, or 1 to 4 carbon atoms. In manyembodiments of Formula (I-C), —OR¹⁰ is an alkoxy (i.e., R¹⁰ is analkyl).

In other embodiments of Formulas (I), group R¹ is of formula —N(R³)₂.Such photoinitiators are of Formula (I-B).

These photoinitiators are bis-dithiocarbamate compounds having a singlecarbon atom between the two dithiocarbonate groups.

Each R³ in Formula (I) and Formula (I-B) is an alkyl or two adjacent R³groups are combined with the nitrogen to which they are both attached toform a first heterocyclic ring having at least one heteroatom selectedfrom nitrogen, oxygen, and sulfur, the first heterocyclic ring beingsaturated or unsaturated (e.g., partially or fully unsaturated) andoptionally fused to one or more second rings that are carbocyclic orheterocyclic. Suitable alkyl groups typically have at least 1 carbonatom, at least 2 carbon atoms, at least 3 carbon atoms, or at least 4carbon atoms and can have up to 20 carbon atoms, up to 18 carbon atoms,up to 16 carbon atoms, up to 12 carbon atoms, or up to 10 carbon atoms.Some example alkyl groups have 1 to 20 carbon atoms, 1 to 10 carbonatoms, 2 to 10 carbon atoms, 1 to 6 carbon atoms, 2 to 6 carbon atoms,or 1 to 4 carbon atoms. When the formula —N(R³)₂ forms a firstheterocyclic ring, the heterocyclic ring typically has a first ringstructure with 5 to 7 ring members or 5 to 6 ring members and with 1 to3 heteroatoms or 1 to 2 heteroatoms in the ring. If there is oneheteroatom in the first ring structure, the heteroatom is nitrogen. Ifthere are two or three heteroatoms in the first ring structure, oneheteroatom is nitrogen and any additional heteroatom is selected fromnitrogen, oxygen, and sulfur. The first ring optionally can be fused toone or more second ring structures that are heterocyclic or carbocyclicand saturated or unsaturated (e.g., partially or fully unsaturated). Ifthe second ring structure is heterocyclic, it typically has 5 to 7 or 5to 6 ring members and 1, 2, or 3 heteroatoms selected from nitrogen,oxygen, and sulfur. If the second ring structure is carbocyclic, it isoften benzene or a saturated ring having 5 or 6 ring members. In manyembodiments, the heterocyclic ring has a single ring structure with 5 or6 ring members and with either 1 or 2 heteroatoms in the ring. Examplesof heterocyclic rings include, but are not limited to, morpholino,thiomorpholino, pyrrolidinyl, piperidinyl, homo-piperidinyl, indolyl,carbazolyl, imidazolyl, and pyrazolyl. In many embodiments of Formula(I-B), R³ is an alkyl.

Group R² in Formula (I) (including Formulas (I-A) and (I-B)) is alkyl,aryl, aralkyl, or substituted aryl, wherein the substituted aryl is anaryl substituted with at least one alkyl, alkoxy, halo, or a combinationthereof. When R² is an alkyl, the alkyl group typically has at least 1carbon atom, at least 2 carbon atoms, at least 3 carbon atoms, or atleast 4 carbon atoms and can have up to 20 carbon atoms, up to 18 carbonatoms, up to 16 carbon atoms, up to 12 carbon atoms, or up to 10 carbonatoms. Some example alkyl groups have 1 to 20 carbon atoms, 1 to 10carbon atoms, 2 to 10 carbon atoms, 1 to 6 carbon atoms, 2 to 6 carbonatoms, or 1 to 4 carbon atoms. When R² is an aryl or a substituted aryl,the aryl often has 5 to 12 carbon atoms, 6 to 12 carbon atoms, or 6 to10 carbon atoms. The aryl is often phenyl. Alkyl or alkoxy groups thatare substituents of the aryl group typically have 1 to 10 carbon atoms,1 to 6 carbon atoms, or 1 to 4 carbon atoms. Halo groups that aresubstituents of the aryl group typically are bromo, chloro, fluoro, oriodo. A combination of the substituents means that the aryl issubstituted with two substituents and they are not of the same type.Alternatively, the listed substituents can be combined together into asingle substituent. For example, a combined substituent can be a halosubstituted alkyl or alkoxy group. When R² is an aralkyl, the aralkylgroup often contains an alkylene group having 1 to 10 carbon atoms, 1 to6 carbon atoms, or 1 to 4 carbon atoms and an aryl group having 5 to 12carbon atoms, 6 to 12 carbon atoms, or 6 to 10 carbon atoms. The arylgroup in the aralkyl group is often phenyl.

The photoinitiator compounds of Formula (I) can be formed by anysuitable method. One suitable method is shown in Reaction Scheme A.

In this reaction scheme, a dihalo ketone compound (compound (4)) isreacted with a compound of formula R¹—(CS)—S⁻M⁺, which is compound (3)as shown in Reaction II. Compound (3) can be formed, for example, bytreating a salt of formula (1) with carbon disulfide (Reaction I).Compound (1) is a salt of an alkoxide, aryloxide, or amine where M+ isan alkali metal, a tetralkyl ammonium ion, a trialkyl ammonium ion, or adialkylammonium ion. Reaction I is often conducted at temperaturesbetween about 0° C. and about 80° C. in the presence of an organicsolvent such as acetone, acetonitrile, or an alcohol. The reaction(Reaction II) of compound (4) with compound (3) is typically conductedat temperatures between about 0° C. and about 80° C. in the presence ofan organic solvent such as acetone, acetonitrile, or an alcohol.

In some examples of Reaction Scheme A, commercially available compoundsof formula R²—(CO)—CHCl₂ and R²—CO—CHBr₂ (compound (4)) include1,1-dichloropropan-2-one, 2,2-dichloro-1-phenyl-ethanone,2,2-dibromo-1-(4-bromophenyl)ethenone,1,1-dichloro-3,3-dimethyl-2-butanone, and1,1-dichloro-3,3-dimethyl-2-butanone. Examples of compound (3) include,but are not limited to, sodium diethyldithiocarbamate trihydrate andvarious xanthate salts such as potassium ethyl xanthate, sodium ethylxanthate, potassium isopropyl xanthate, sodium isopropyl xanthate, andpotassium amyl xanthate.

The photoinitiator of Formula (I) (including those of Formulas (I-A),(I-B), and (I-C)) is mixed with one or more monomer compositions to forma polymeric materials of Formula (II).

In Formula (II), groups R¹ and R² are the same as defined for thephotoinitiator of Formula (I). Each P is a polymeric block that includesa polymerized product of a monomer composition containing at least onemonomer having a single ethylenically unsaturated group, y is an integerequal to at least 1 (e.g., in a range of 1 to 10, in a range of 1 to 5,or in a range of 1 to 3), and z is an integer in a range of 0 toy. Inmany embodiments z is equal to y. The variable z and y refer to thenumber of polymeric blocks. That is, (P)_(y) means that there are ypolymeric blocks P and (P)_(z) means that there are z polymeric blocksP. The molecular weight of each polymeric block can be the same ordifferent.

Each polymeric block P in Formula (II) is the polymerized product of amonomer composition containing at least one monomer having a singleethylenically unsaturated group. Any monomer having a singleethylenically unsaturated group can be used based on the desiredproperties of the resulting polymeric material. In some embodiments, allthe monomers used to form any polymeric block P have a single(meth)acryloyl group. In other embodiments, all the monomers used toform any polymeric block P have a single ethylenically unsaturated groupthat is not a (meth)acryloyl group. In still other embodiments, all themonomers used to form any polymeric block P have a single ethylenicallyunsaturated group and some, but not all, of the ethylenicallyunsaturated groups are (meth)acryloyl groups. Each polymeric block canbe a homopolymer or a copolymer. Any monomer can be used alone or incombination with other monomers to form each polymeric block.

Suitable monomers with a single (meth)acryloyl group that can be used toform the polymeric material of Formula (II) include, but are not limitedto, alkyl (meth)acrylates, fluorinated alkyl (meth)acrylates, aryl(meth)acrylates, aralkyl (meth)acrylates, substituted aryl(meth)acrylates, (meth)acrylic acid, (meth)acrylamide, N-alkyl(meth)acrylamides, N,N-dialkyl (meth)acrylamides, N-alkylaminoalkyl(meth)acrylates, N,N-dialkylaminoalkyl (meth)acrylates,N-alkylaminoalkyl (meth)acrylamides, N,N-dialkylaminoalkyl(meth)acrylamides, hydroxy-substituted alkyl (meth)acrylates,hydroxy-substituted alkyl (meth)acrylamides, alkoxylated alkyl(meth)acrylates, acid-substituted alkyl (meth)acrylates,acid-substituted alkyl (meth)acrylamides, glycidyl-containing(meth)acrylates, isocyanate-containing (meth)acrylates such asisocyanate-substituted alkyl (meth)acrylates, aminosulfonyl-containing(meth)acrylates, cationic monomers such as N,N,N-trialkylaminoalkyl(meth)acrylates, zwitterionic monomers (e.g.,2-(N-3-sulfopropyl-N,N-dime thylammonium)ethyl (meth)acrylate), andmixtures thereof. A plurality of different monomers having a single(meth)acryloyl group can be included in the monomer composition for anypolymeric block.

In other embodiments, the reaction mixture used to form any block P inthe polymeric material of Formula (II) includes a monomer compositioncontaining a monomer having a single ethylenically unsaturated groupthat is not a (meth)acryloyl group. Suitable such monomers include, butare not limited to, N-vinylpyrrolidone, N-vinylcaprolactam, vinylacetate, vinyl methyl ether, vinyl-2-ethylhexanoate, vinyl neodecanoate,styrene, isoprene, butadiene, vinyl dimethylazlactone (VDM), isopropenyldimethylazlactone (IDM), and vinyl oxazole, and the like.

In Formula (II), the variables y and z refer to the number of polymericblocks P. The variable y is an integer equal to at least 1 (e.g., in arange of 1 to 10, in a range of 1 to 5, in a range of 1 to 3, or in arange of 1 to 2) and the variable z is an integer in a range of 0 to y.If the variable y is equal to 1, the variable z is equal to 0 or 1. If zis equal to 0, then the resulting polymeric material has amono-directional polymeric group. That is, there is a polymeric chainonly on one side of the divalent group —CH[(CO)R²]— in Formula (II). Ifz is equal to 1, then the resulting polymeric material has abi-directional polymeric group. That is, there is a polymeric group onboth sides of the divalent group —CH[(CO)R²]— in Formula (II).

In some embodiments, the polymeric material formed in the early stagesof polymerization of the monomer composition results in the formation ofa polymeric chain growing on one but not on both sides of the divalentgroup —CH[(CO)R²]— in Formula (II). That is, the reaction product ispredominately a polymeric material having y equal to 1 and z equal to 0.As polymerization proceeds, the reaction product includes a mixture of afirst polymeric material having y equal to 1 and z equal to 0 (i.e.,this first polymeric material can be referred to as a “mono-directionalpolymeric material”) and a second polymeric material having y equal to 1and z equal to 1 (i.e., this second polymeric material can be referredto as a “bi-directional polymeric material”). As the extent ofpolymerization (i.e., conversion of the monomer composition) increases,the percentage of the polymeric material that is bi-directionaltypically increases. When the conversion is at least 90 percent, theamount of bi-directional polymeric material is often at least 80 weightpercent, at least 90 weight percent, or at least 95 weight percent basedon the total weight of polymeric material (i.e., the mono-directionalplus bi-directional polymeric material).

Some polymeric materials of Formula (II) are formed from thephotoinitiators of Formula (I-A) and are of Formula (II-A).

In Formula (II-A), group R¹⁰ is the same as defined in Formula (I-A).Groups R² and P as well as the variables y and z are the same as definedin Formula (II).

Some polymeric materials of Formula (II) are formed from thephotoinitiators of Formula (I-C) and are of Formula (II-C).

In Formula (II-C), groups R¹⁰, R²⁰, and P as well as the variables y andz are the same as defined in Formulas (I-C) and (II).

Some polymeric materials of Formula (II) are formed from thephotoinitiators of Formula (I-B) and are of Formula (II-B).

In Formula (II-B), groups R², R³, and P as well as the variables y and zare the same as defined in Formulas (I-B) and (II).

While not wishing to be bound by theory, it is believed thatpolymerization occurs as shown in Reaction Scheme B to form a materialwhere y is equal to 1 and z is equal to either 0 or 1.

In Reaction Scheme B, the photoinitiator of Formula (I), which is shownas compound (10), undergoes photolysis of one of the C—S bonds whenexposed to actinic radiation (e.g., ultraviolet radiation) (ReactionIII). Two different radicals, the radical (11) and the radical (12), areformed in Reaction III. In Reaction IV, radical (11) reacts withethylenically unsaturated monomers (compound (13)). The monomerspolymerize and radical (14) is formed. The radical (14) can combine witha radical (12) and the polymerization reaction is terminated. Theresulting polymeric material of Reaction V is compound (15). Compound(15) corresponds to the polymeric material of Formula (II) where y isequal to 1 and z is equal to zero (i.e., there is polymeric material ononly one side of the —CH[(CO)R²]— group; the polymeric material ismono-directional). Compound (15) can undergo photolysis at one of theC—S bonds in the presence of actinic radiation (e.g., ultravioletradiation). Photolysis can result in the generation of radical (12) andradical (16) as shown in Reaction VI. In Reaction VII, radical (16)reacts with ethylenically unsaturated monomers (compound 13). Themonomers polymerize and radical (17) is formed. The radical (17) cancombine with radical (12) and the polymerization reaction is terminated.The resulting polymeric material formed in Reaction VIII is compound(18). Compound (18) corresponds to the polymeric material of Formula(II) where y is equal to 1 and z is equal to 1 (i.e., there is polymericmaterial on both sides of the —CH[(CO)R²]— group; the polymeric materialis bi-directional). While exposure to actinic radiation (e.g.,ultraviolet radiation) continues, photolysis of compound (18) can occurand additional monomeric units can be added. When exposure to actinicradiation (e.g., ultraviolet radiation) is terminated, no furtherphotolysis can occur, and no additional monomeric units can be added.

Additionally, the dithiocarbonate or dithiocarbamate chain end may bedirectly transferred between polymeric chains in anaddition-fragmentation process. In Reaction IX, for example, radical(14) combines with another molecule of compound (15) to generate radical(19). In Reaction X, radical (19) undergoes homolysis of a carbon-sulfurbond to regenerate radical (14) and compound (15). In Reaction (XI),radical (19) undergoes homolysis on the opposite side of thedithiocarbonate or dithiocarbamate group to generate compound (15) andradical (16), a net transfer of the dithiocarbonate or dithiocarbamategroup.

In Reaction Scheme B, compound (13) is a monomer having a singleethylenically unsaturated group. If the ethylenically unsaturated groupis a (meth)acryloyl group, W is hydrogen or methyl and W includes agroup —(CO)—X—R¹¹. Group X is oxy or —NR¹²— where W² is hydrogen oralkyl. Group R¹¹ is the remainder of the (meth)acryloyl-containingmonomer. That is, the monomer is of formula H₂C═CR^(x)—(CO)—X—R₁₁. GroupR¹¹ is hydrogen or methyl and group R¹¹ is the remainder, for example,of any (meth)acrylate or (meth)acrylamide monomer described herein.

Polymeric materials of Formula (II) with y equal to 1 can be formed bymixing a photoinitiator of Formula (I) with a monomer composition 1A andexposing the resulting reaction mixture 1A to actinic radiation (e.g.,ultraviolet light). The actinic radiation exposure causes the photolysisof the photoinitiator and permits controlled radical polymerization ofthe monomer composition 1A to form a first polymeric block. Whenexposure to actinic radiation is terminated, the first polymerizationreaction ceases. The product of the first polymerization is a polymericmaterial of Formula (II-1) where (P)₁ indicates that there is onepolymeric block and (P)₀₋₁ indicates that there is zero to one polymericblocks.

There may be a first polymeric block P¹ on only one side of the—CH[(CO)R²]— group as in the polymeric material of Formula (II-1B)(i.e., z in Formula (II) is equal to 0) or on both sides of the—CH[(CO)R²]— group as in the polymeric material of Formula (II-1A)(i.e., z in Formula (II) is equal to 1). The length of the polymericchains P¹ on either side of the —CH[(CO)R²]— group in the polymericmaterial of Formula (II-1A) can be the same or different.

In some embodiments, there may be a polymeric block only on one side ofthe —CH[(CO)R²]— group. That is, the variable y is equal to 1 and thevariable z is equal to 0 as shown in the polymeric material of Formula(II-IB). Thus, the photoinitiator can be mono-directional in terms ofpolymeric chain formation. This can be particularly the situation duringthe early stages of conversion. As the polymerization reaction proceeds,polymerization may occur on both sides of the —CH[(CO)R²]— group. Thatis, the variable y is equal to 1 and the variable z is equal to 1 in thepolymeric material of Formula (II) as shown in Formula (II-1A). In suchpolymeric material, the size (e.g., the number average molecular weight)of the two polymeric blocks will be different.

In other embodiments, the photoinitiator can be bi-directional in termsof polymeric chain formation. That is, there will be a polymeric blockon both sides of the —CH[(CO)R²]— group. The variable y is equal to 1and the variable z is equal to 1 in the polymeric material of Formula(II). Even though there is a polymeric block on either side of the—CH[(CO)R²]— group, the size (e.g., the number average molecular weight)of the two polymeric blocks can be the same or different.

Another monomer composition, referred to as monomer composition 1B, canbe added to the product of the reaction mixture 1A (i.e., the polymericmaterial of Formula (II-1A) and/or Formula (II-1B)) to form a reactionmixture 1B. Upon exposure of the reaction mixture 1B to actinicradiation, photolysis occurs again releasing the radical of formulaR¹—(CS)—S*. Monomer composition 1B can polymerize to form a secondpolymeric block P² attached to the end of any polymeric block P¹ in thepolymeric material of Formula (II-1-1) or (II-1-2). When exposure toactinic radiation is terminated, the second polymerization reactionceases. If there are two polymeric blocks (P¹ and P²), the length of thetwo polymeric chains can be the same or different. The product of thesecond polymerization is the polymeric material of Formula (II-2). Thedesignation (P)₂ indicates that there are two polymeric blocks and thedesignation (P)₀₋₂ indicates that are 0 to 2 polymeric blocks.

The number of polymeric blocks on each side of the —CH[(CO)R²]— group inFormula (II-2) can be the same or different. That is, although there canbe two blocks on one side of this group, there can be 0, 1 or 2 blockson the other side. Stated differently, in Formula (II), y is 2 and z is0, 1, or 2. If a polymeric block is on both sides of the —CH[(CO)R²]—group, the size (e.g., number average molecular weight) of the polymericblocks can be the same or different.

In many embodiments of Formula (II-2), both z and y are equal to 2 andthe polymeric material is of formula (II-2A).

P¹ refers to the first polymeric block and P² refers to the secondpolymeric block.

This process can be repeated as many times as desired to add additionalpolymeric blocks. For example, in the polymeric material of Formula(II-3), the designation (P)₃ indicates that there are three polymericblocks (i.e., y is equal to 3 in Formula (II)) and the designation(P)₀₋₃ indicates that there are 0 to 3 polymeric blocks (i.e., z is in arange of 0 to 3 in Formula (II)).

In many embodiments of Formula (III-3), both z and y are equal to 3 andthe polymeric material is of formula (II-3A).

P¹ refers to the first polymeric block, P² refers to the secondpolymeric block, and P³ refers to the third polymeric block.

This ability to control the architecture of the resulting polymericmaterial is particularly advantageous when block copolymers areprepared. By first polymerizing a monomer composition 1A and thenpolymerizing a monomer composition 1B that is different than monomercomposition 1A, a polymeric material composition that is primarily adiblock copolymer, that is primarily a triblock copolymer, or a mixturethereof can be formed depending on the specific photoinitiator that isselected.

Each polymeric block (e.g., P, P¹, P², or P³) can have any desiredmolecular weight. The molecular weight of each block can be the same ordifferent than any other polymeric block. In some embodiments, theweight average molecular weight of any polymeric block is at least 1,000Daltons, at least 2,000 Daltons, at least 5,000 Daltons, at least 10,000Daltons, at least 20,000 Daltons, at least 50,000 Daltons, or at least100,000 Daltons. The weight average molecular weight of any polymericblock can be up to 1 million Daltons or even higher, up to 750,000Daltons, up to 500,000 Daltons, up to 200,000 Daltons, or up to 100,000Daltons. In some embodiments, the polymeric material of Formula (II) hasan overall weight average molecular weight in a range of 10,000 Daltonsto 5 million Daltons, in a range of 10,000 Daltons to 3 million Daltons,or in a range of 10,000 Daltons to 1 million Daltons.

For polymeric materials having multiple polymeric blocks on at least oneside of the —CH[(CO)R²]— group, different monomer compositions aretypically used for each polymeric block. For example, the firstpolymeric block P¹ is a polymerized product of a monomer composition 1Acontaining at least one monomer having a single ethylenicallyunsaturated group. P² is a second polymeric block that is a polymerizedproduct of a monomer composition 1B containing at least one monomerhaving a single ethylenically unsaturated group. The composition of thesecond polymeric block P² is different than the composition of the firstpolymeric block P¹. If another polymeric block P³ were added that is apolymerized product of a monomer composition 1C, the composition of thethird block is usually selected to be different than the secondpolymeric block P² and can be selected to be the same or different thanthe composition of the first polymeric block P¹. Stated differently,monomer composition 1A is different than monomer composition 1B andmonomer composition 1B is different than monomer composition 1C. Monomercomposition 1A can be the same or different than monomer composition 1C.Each polymeric block can be a homopolymer or a copolymer. If any blockis a copolymer, it is typically a random copolymer.

To form a polymeric material of Formula (II) where y is equal to 1 and zis equal to 0 or 1, the photoinitiator of Formula (I) is mixed with amonomer composition 1A (i.e., first monomer composition 1A) to form areaction mixture 1A (i.e., first reaction mixture 1A). Exposing reactionmixture 1A to actinic radiation (e.g., ultraviolet radiation) causesphotolysis of the photoinitiator and permits controlled radicalpolymerization of the monomer composition 1A. When exposure to actinicradiation (e.g., ultraviolet radiation) is terminated, thepolymerization reaction ceases. The product of reaction mixture 1A is apolymeric material of Formula (II-1).

More specifically, to prepare a polymeric material of Formula (II-1),monomer composition 1A (e.g., a first monomer composition) is mixed witha photoinitiator of Formula (I) to form reaction mixture 1A. Reactionmixture 1A can be neat (i.e., no solvent is present) or can be mixedwith a solvent that dissolves both the monomer composition 1A and thephotoinitiator of Formula (I). The solvent can be added, for example, tolower the viscosity of the first reaction mixture. Any solvent that isadded is usually selected so that the growing polymeric material is alsosoluble. In some embodiments, the percent solids in reaction mixture 1Ais at least 10 weight percent, at least 20 weight percent, at least 30weight percent, or at least 40 weight percent and up to 100 weightpercent, up to 80 weight percent, or up to 60 weight percent. The amountof solvent added is often selected based on the desired viscosity,particularly the viscosity of the final polymerized material. Thedesired viscosity is usually sufficiently low so that the finalpolymeric material can be readily removed from the reactor and/orapplied to a substrate.

If a solvent is added, the solvent is often an ester (e.g., ethylacetate, butyl acetate, and ethylene glycol monomethyl ether acetate),an ether (e.g., dimethyl ether, diethyl ether, ethyl propyl ether,dipropyl ether, methyl t-butyl ether, di-t-butyl ether, dimethoxyethane, 2-methoxyethanol, diethylene glycol dimethyl ether, dioxane, andtetrahydrofuran), acetonitrile, methylene chloride, an aromatichydrocarbon (e.g., benzene, xylene, and toluene), or a ketone (e.g.,acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone,and cyclohexanone). Mixtures of solvents can be used. Further, one ormore solvents can be combined with water, if miscible. Polymerization ofthe monomer composition 1A can start at room temperature (e.g., about20° C. to 25° C.) but can also start, if desired at higher or lowertemperatures.

Reaction mixture 1A is exposed to actinic radiation (e.g., ultravioletradiation) to activate the photoinitiator of Formula (I) and commencecontrolled radical polymerization of monomer composition 1A. Theresulting polymeric block P¹ can be a homopolymer or a random copolymer.

Unless the polymeric material will be crosslinked with a crosslinkingmonomer having at least two ethylenically unsaturated groups,polymerization of reaction mixture 1A is usually allowed to proceeduntil greater than 80 weight percent, greater than 85 weight percent,greater than 90 weight percent, greater than 95 weight percent, greaterthan 98 weight percent, greater than 99 weight percent, or 100 weightpercent of the monomers in the monomer composition 1A have undergonecontrolled radical polymerization. Alternatively, unreacted monomers canbe removed from the polymerized material. One of skill in the art isfamiliar with methods of separating the polymeric material from residualmonomers.

Alternatively, if the polymeric material will be crosslinked with amonomer having at least two ethylenically unsaturated groups,polymerization of reaction mixture 1A can be allowed to proceed to anydesired extent until at least 5 weight percent of the monomercomposition 1A has undergone controlled radical polymerization. Forexample, the polymerization reaction can proceed until at least 10weight percent, at least 20 weight percent, at least 30 weight percent,at least 40 weight percent and up to 100 weight percent, up to 99 weightpercent, up to 98 weight percent, up to 95 weight percent, up to 90weight percent, up to 85 weight percent, up to 80 weight percent ormore, up to 70 weight percent, up to 60 weight percent, or up to 50weight percent of the monomer composition 1A has undergone controlledradical polymerization. The resulting polymeric material can be combinedwith a second monomer composition containing a crosslinking monomerhaving at least two ethylenically unsaturated groups to form acrosslinkable composition.

Advantageously, the photoinitiators of Formula (I) are very efficient.During the early stages of polymerization quite a few polymeric chainsare initiated and the average molecular weight (both number average andweight average molecular weights) of the formed polymeric material islow. As the polymerization reaction progresses, the average molecularweight tends to increase. In contrast, with many other photoinitiators,even those having both a group of formula —S—(CS)—R′ and a ketone groupsuch as photoinitiators PI-1 to PI-3 in the Example section, during theearly stages of polymerization only a few polymeric chains are initiatedand the average molecular weight (both number average and weight averagemolecular weights) of the formed polymeric material is quite high. Asthe polymerization reaction progresses, the average molecular weighttends to decrease.

Polymeric materials having more than one polymeric block can be formedfrom the polymeric material of Formula (II-1). A monomer composition 1Bcan be added to the polymeric material of Formula (II-1) to formreaction mixture 1B. Upon exposure of reaction mixture 1B to actinicradiation (e.g., ultraviolet radiation), photolysis occurs againreleasing the radical of formula R¹—(CS)—S*. Monomer composition 1B canpolymerize to form a second polymeric block P² attached to a firstpolymeric block P¹ in the polymeric material of Formula (II-1). Whenexposure to actinic radiation (e.g., ultraviolet radiation) isterminated, the polymerization reaction ceases. The product of thereaction mixture 1B is the polymeric material of Formula (II-2).

More specifically, a polymeric material of Formula (II-2) can be formedfrom the polymeric material of Formula (II-1). After 80 weight percentor more (such as at least 90 weight percent, at least 95 weight percent,at least 98 weight percent, at least 99 weight percent, or 100 weightpercent) of the monomer composition 1A has undergone controlled radicalpolymerization, the polymerization reaction is stopped by terminatingexposure to actinic radiation (e.g., ultraviolet radiation). A reactionmixture 1B is formed by adding a monomer composition 1B to the reactionproduct of the reaction mixture 1A. The reaction mixture 1B includes afirst polymeric material of Formula (II) plus a monomer composition 1Bhaving at least one monomer with a single ethylenically unsaturatedgroup. It is typically not necessary to add further photoinitiator ofFormula (I) to reaction mixture 1B.

Any optional solvent that is included in reaction mixture 1B is usuallyselected so that it solubilizes the first polymeric material of Formula(II-1), the photoinitiator of Formula (I), and monomer composition 1B.That is, reaction mixture 1B is typically a single phase. In someembodiments, the percent solids in reaction mixture 1B is selected tohave percent solids equal to at least 10 weight percent, at least 20weight percent, at least 30 weight percent, or at least 40 weightpercent and up to 100 weight percent (i.e., no solvent is added), up to80 weight percent, or up to 60 weight percent. Suitable solvents are thesame as those discussed above for the reaction mixture 1A. The amount ofsolvent added is selected based on the desired viscosity, particularlythe viscosity of the final polymerized material. The desired viscosityis usually sufficiently low so that the final polymeric material can bereadily removed from the reactor and/or applied to a substrate.

Reaction mixture 1B is exposed to actinic radiation (e.g., ultravioletradiation) to commence controlled radical polymerization of monomercomposition 1B. Polymerization of the second monomer composition canoccur at room temperature (e.g., about 20° C. to 25° C.) but can alsooccur, if desired at higher or lower temperatures.

Unless the polymeric material will be crosslinked with a crosslinkingmonomer having at least two ethylenically unsaturated groups, thepolymerization of reaction mixture 1B is usually allowed to proceeduntil greater than 80 weight percent, greater than 85 weight percent,greater than 90 weight percent, greater than 95 weight percent, greaterthan 98 weight percent, greater than 99 weight percent, or 100 weightpercent of the monomers in the monomer composition 1B have undergonecontrolled radical polymerization. Alternatively, unreacted monomers canbe removed from the polymerized material. One of skill in the art isfamiliar with methods of separating the polymeric material from residualmonomers.

If the polymeric material will be crosslinked with a crosslinkingmonomer having at least two ethylenically unsaturated groups,polymerization of reaction mixture 1B can be allowed to proceed to anydesired extent until at least 5 weight percent of the monomercomposition 1B has undergone controlled radical polymerization. Forexample, the polymerization reaction can proceed until at least 10weight percent, at least 20 weight percent, at least 30 weight percent,at least 40 weight percent and up to 100 weight percent, up to 99 weightpercent, up to 98 weight percent, up to 95 weight percent, up to 90weight percent, up to 85 weight percent, up to 80 weight percent ormore, up to 70 weight percent, up to 60 weight percent, or up to 50weight percent of the monomer composition 1B has undergone controlledradical polymerization. The resulting polymeric material can be combinedwith a second monomer composition containing a crosslinking monomerhaving at least two ethylenically unsaturated groups to form thecrosslinkable composition.

The composition of polymeric block P² is typically different than thecomposition of polymeric block P¹. In some embodiments, the polymericblocks P¹ and P² have different glass transition temperatures asmeasured by Differential Scanning calorimetry. In some embodiments, thedifference in the glass transition temperature of polymeric blocks P¹and P² is at least 40° C., at least 50° C., at least 60° C., at least70° C., at least 80° C., at least 90° C., or at least 100° C. It isoften preferable, that the polymeric material of Formula (II) is solublein reaction mixture 1B containing monomer composition 1B used to formthe polymeric material of Formula (III).

In some embodiments, it is desirable to have sharp transitions betweenthe first polymeric block P¹ and the second polymeric blocks P². Thetransition between two polymeric blocks can be controlled by the percentconversion of reaction mixture 1A to the first polymeric block. If thepercent conversion is relatively low (e.g., less than 90 percent), thenthe reaction mixture 1B will include a mixture of the monomercomposition 1B plus remaining unreacted monomer composition 1A. That is,some of the monomers from the monomer composition 1A will be in thesecond polymeric block P². To minimize the presence of monomeric unitsof monomer composition 1A in the second polymeric block P², the percentconversion of the monomer composition 1A should be maximized. A higherpercent conversion must be balanced, however, against a longer reactiontime. Alternatively, the transition between two polymeric blocks can becontrolled by removal of unreacted monomers from the polymerizedmaterial. One of skill in the art is familiar with methods of separatingthe polymeric material from residual monomers.

A polymeric material of Formula (II-3) can be formed from the polymericmaterial of Formula (II-2). After 80 weight percent or more (such as atleast 90 weight percent, at least 95 weight percent, at least 98 weightpercent, at least 99 weight percent, or 100 weight percent) of themonomer composition 1B used to form the polymer of Formula (II-2) hasundergone controlled radical polymerization, the polymerization reactionis stopped by terminating exposure to actinic radiation (e.g.,ultraviolet radiation). A reaction mixture 1C is formed by adding amonomer composition 1C to the reaction product of the reaction mixture1B. The reaction mixture 1C includes a second polymeric material ofFormula (II-2) plus a monomer composition 1C having at least one monomerwith a single ethylenically unsaturated group.

Any optional solvent that is included in the reaction mixture 1C isusually selected so that it solubilizes the polymeric material ofFormula (II-2), the photoinitiator of Formula (I), and the monomercomposition 1C. That is, the reaction mixture 1C is typically a singlephase. In some embodiments, the percent solids in the reaction mixture1C is selected to have percent solids equal to at least 10 weightpercent, at least 20 weight percent, at least 30 weight percent, or atleast 40 weight percent and up to 100 weight percent (i.e., no solventis added), up to 80 weight percent, or up to 60 weight percent. Suitablesolvents are the same as those discussed above for the reaction mixture1A. The amount of solvent added is selected based on the desiredviscosity, particularly the viscosity of the final polymerized material.The desired viscosity is usually sufficiently low so that the finalpolymeric material can be readily removed from the reactor and/orapplied to a substrate.

The reaction mixture 1C is exposed to actinic radiation (e.g.,ultraviolet radiation) to commence controlled radical polymerization ofthe monomer composition 1C. The resulting P³ block or blocks can be ahomopolymer or a random copolymer. Polymerization of the monomercomposition 1C can occur at room temperature (e.g., about 20° C. to 25°C.) but can also occur, if desired at higher or lower temperatures.

Unless the polymeric material will be crosslinked with a crosslinkingmonomer having at least two ethylenically unsaturated groups,polymerization the polymerization of reaction mixture 1C is usuallyallowed to proceed until greater than 80 weight percent, greater than 85weight percent, greater than 90 weight percent, greater than 95 weightpercent, greater than 98 weight percent, greater than 99 weight percent,or 100 weight percent of the monomers in the monomer composition 1C haveundergone controlled radical polymerization. Alternatively, unreactedmonomers can be removed from the polymerized material. One of skill inthe art is familiar with methods of separating the polymeric materialfrom residual monomers.

If the polymeric material will be crosslinked with a crosslinkingmonomer having at least two ethylenically unsaturated groups,polymerization of reaction mixture 1C can be allowed to proceed to anydesired extent until at least 5 weight percent of the monomercomposition 1C has undergone controlled radical polymerization. Forexample, the polymerization reaction can proceed until at least 10weight percent, at least 20 weight percent, at least 30 weight percent,at least 40 weight percent and up to 100 weight percent, up to 99 weightpercent, up to 98 weight percent, up to 95 weight percent, up to 90weight percent, up to 85 weight percent, up to 80 weight percent ormore, up to 70 weight percent, up to 60 weight percent, or up to 50weight percent of the monomer composition 1C has undergone controlledradical polymerization. The resulting polymeric material can be combinedwith a second monomer composition containing a crosslinking monomerhaving at least two ethylenically unsaturated groups to form thecrosslinkable composition.

The composition of polymeric block P³ is typically different than thecomposition of polymeric block P², the composition of polymeric block P²is typically different than the composition of polymeric block P¹, andthe composition of polymeric block P³ can be the same or different thanthe composition of polymeric block P¹. In some embodiments, thepolymeric blocks P³ and P² have different glass transition temperaturesand the polymeric blocks P² and P¹ have different glass transitiontemperatures as measured by Differential Scanning calorimetry. In someembodiments, the difference in the glass transition temperature betweenthe polymeric blocks is at least 40° C., at least 50° C., at least 60°C., at least 70° C., at least 80° C., at least 90° C., or at least 100°C.

Additional polymeric blocks can be added to the polymeric material ofFormula (II-3) to form polymeric materials of Formula (II) where thevariable y is greater than 3 and z is in a range of 0 to y. Eachsuccessive precursor polymeric material is added to another monomercomposition to form another reaction mixture. The reaction mixture isexposed to actinic radiation such as ultraviolet radiation to form thepolymeric material with two additional polymeric blocks as describedabove.

Adjacent polymeric blocks typically have different compositions,different glass transition temperatures, and different solubilityparameters. Because of these differences, a phase separated morphologymay result. This phase separation leads to physical crosslinking withinthe block copolymer and can, for example, increase the cohesive strengthof the polymeric material even in the absence of chemical crosslinks.

The amount of the photoinitiator of Formula (I) included in the reactionmixture for any block impacts the weight average molecular weight of theresulting polymeric block. That is, the weight average molecular weightcan be controlled based on the amount of photoinitiator added to thereaction mixture. The amount of photoinitiator is typically in a rangeof 0.001 to 15 weight percent based on the weight of the monomers in thereaction mixture. For comparable reaction conditions, increasing theamount of photoinitiator tends to decrease the weight average molecularweight (as well as the number average molecular weight). The amount ofthe photoinitiator is typically at least 0.001 weight percent, at least0.005 weight percent, at least 0.01 weight percent, at least 0.02 weightpercent, at least 0.03 weight percent, or at least 0.5 weight percentand can be up to 15 weight percent, up to 12 weight percent, up to 10weight percent, up to 8 weight percent, up to 6 weight percent, up to 5weight percent, up to 3 weight percent, up to 2 weight percent, or up to1 weight percent. This amount of photoinitiator often results in theformation of polymeric blocks having a weight average molecular weightin a range of 1,000 to 3,000,000 Daltons or in the range of 1,000 to 1million Daltons.

The reaction mixtures used to form the polymeric material of Formula(II) typically do not include a chain transfer agent (such as mercaptansand carbon tetrabromide). Chain transfer agents are not needed tocontrol the molecular weight of the resulting polymeric material.Rather, the molecular weight can be varied and controlled throughselection of the desired amount of the photoinitiator of Formula (I) andof the desired reaction temperature.

For crosslinking, the polymeric material of Formula (II) (e.g., thepolymeric material of Formula (II-1), (II-2), or (II-3)) is combinedwith a second monomer composition to provide a crosslinkablecomposition. The second monomer composition contains a crosslinkingmonomer having at least two ethylenically unsaturated groups.Optionally, the second monomer composition can also include one or moremonomers having a single ethylenically unsaturated group. The polymericmaterial can have any desired number of polymeric blocks.

The polymeric material of Formula (II) that is combined with the secondmonomer composition in the crosslinkable composition can have anydesired extent of polymerization in the outer block (e.g., polymer blockP¹ in Formulas (II-1) and polymer block P² in Formulas (II-2). In someembodiments, the outer blocks are fully polymerized (e.g., the outerblocks are greater than 99 weight percent polymerized based on theweight of monomers used to form the outer block), nearly fullypolymerized (e.g., the outer blocks are at least 80 to 99 weight percentpolymerized based on the weight of the monomers used to form the outerblocks), or are partially polymerized (e.g., 5 to 80 weight percentpolymerized based on the weight of the monomers used to form the outerblocks). Polymeric material of Formula (II) with partially polymerizedouter blocks are referred to as “syrup polymers”.

Syrup polymers often includes 5 to 80 weight percent polymeric materialof Formula (II) and 20 to 95 weight percent monomer having a singleethylenically unsaturated group based on a total weight of polymerized(i.e., reacted monomers) and polymerizable material (i.e., unreactedmonomers). In some embodiments, the syrup polymer contains 10 to 80weight percent polymeric material of Formula (II) and 20 to 90 weightpercent monomer having a single ethylenically unsaturated group, 10 to70 weight percent polymeric material of Formula (II) and 30 to 90 weightpercent monomer having a single ethylenically unsaturated group, 10 to60 weight percent polymeric material of Formula (II) and 40 to 90 weightpercent monomer having a single ethylenically unsaturated group, 10 to50 weight percent polymeric material of Formula (II) and 50 to 90 weightpercent monomer having a single ethylenically unsaturated group, 10 to40 weight percent polymeric material of Formula (II) and 60 to 90 weightpercent monomer having a single ethylenically unsaturated group, 20 to50 weight percent polymeric material of Formula (II) and 50 to 80 weightpercent monomer having a single ethylenically unsaturated group, or 20to 40 weight percent polymeric material of Formula (II) and 60 to 80weight percent monomer having a single ethylenically unsaturated group.The amounts are based on a total weight of polymerized and polymerizablematerial.

If a syrup polymer is used in the crosslinkable composition, the secondmonomer composition includes a crosslinking monomer plus any unreactedmonomers (i.e., monomers having a single ethylenically unsaturatedgroup) that were present when the polymer of Formula (II) was formed.Optionally, the second monomer composition can further include othermonomers having a single ethylenically unsaturated group that were notpresent when the polymer of Formula (I) was formed.

Suitable crosslinking monomers often contain at least two (meth)acryloylgroups, which are often acryloyl groups. Exemplary crosslinking monomerswith two (meth)acryloyl groups include 1,2-ethanediol diacrylate,1,3-propanediol diacrylate, 1,4-butanediol diacrylate, 1,4-butanedioldiacrylate, 1,6-hexanediol diacrylate (HDDA), 1,9-nonanediol diacrylate,1,12-dodecanediol diacrylate, butylene glycol diacrylate, bisphenol Adiacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate,tetraethylene glycol diacrylate, tripropylene glycol diacrylate,polyethylene glycol diacrylate, polypropylene glycol diacrylate,polyethylene/polypropylene copolymer diacrylate, and neopentylglycolhydroxypivalate diacrylate modified caprolactone. Exemplary crosslinkingmonomers with three or four (meth)acryloyl groups include, but are notlimited to, trimethylolpropane triacrylate (e.g., commercially availableunder the trade designation TMPTA-N from Surface Specialties, Smyrna,Ga. and under the trade designation SR-351 from Sartomer, Exton, Pa.),pentaerythritol triacrylate (e.g., commercially available under thetrade designation SR-444 from Sartomer),tris(2-hydroxyethylisocyanurate) triacrylate (commercially availableunder the trade designation SR-368 from Sartomer), a mixture ofpentaerythritol triacrylate and pentaerythritol tetraacrylate (e.g.,commercially available from Surface Specialties under the tradedesignation PETIA with an approximately 1:1 ratio of tetraacrylate totriacrylate and under the trade designation PETA-K with an approximately3:1 ratio of tetraacrylate to triacrylate), pentaerythritoltetraacrylate (e.g., commercially available under the trade designationSR-295 from Sartomer), di-trimethylolpropane tetraacrylate (e.g.,commercially available under the trade designation SR-355 fromSartomer), and ethoxylated pentaerythritol tetraacrylate (e.g.,commercially available under the trade designation SR-494 fromSartomer). An exemplary crosslinking monomer with five (meth)acryloylgroups includes, but is not limited to, dipentaerythritol pentaacrylate(e.g., commercially available under the trade designation SR-399 fromSartomer).

Regardless of whether the polymeric material of Formula (II) is a syruppolymer, a nearly fully polymerized polymeric material, or a fullypolymerized polymeric material, the crosslinkable composition usuallyincludes 0.01 to 20 weight percent crosslinking monomer based on a totalweight of polymerized and polymerizable material. In many embodiments,the crosslinkable composition contains at least 0.05 weight percent, atleast 0.1 weight percent, at least 0.5 weight percent, or at least 1weight percent and up to 15 weight percent, up to 10 weight percent, upto 5 weight percent, or up to 1 weight percent crosslinking monomerbased on the total weight of polymerized and polymerizable material. Anyother monomers included in the crosslinkable composition have a singleethylenically unsaturated group.

Thus, the overall crosslinkable composition contains 5 to 99.99 weightpercent polymeric material of Formula (II) and a second monomercomposition containing 1) 0.01 to 20 weight percent crosslinking monomerhaving at least two ethylenically unsaturated groups and 2) 0 to 95weight percent monomer having a single ethylenically unsaturated group.In some embodiments, the crosslinkable composition contains 10 to 99.99weight percent polymeric material of Formula (II) and a second monomercomposition containing 1) 0.01 to 10 weight percent crosslinking monomerhaving at least two ethylenically unsaturated groups and 2) 0 to 90weight percent (0 to 89.99 weight percent) monomers having a singleethylenically unsaturated group. In other embodiments, the crosslinkablecomposition contains 10 to 80 weight percent polymeric material ofFormula (II) and a second monomer composition containing 1) 0.01 to 10weight percent crosslinking monomer having at least two ethylenicallyunsaturated groups and 2) 10 to 90 weight percent monomers (10 to 89.99weight percent) having a single ethylenically unsaturated group. Instill other embodiments, the crosslinkable composition contains 10 to 60weight percent polymeric material of Formula (II) and a second monomercomposition containing 1) 0.01 to 10 weight percent crosslinking monomerhaving at least two ethylenically unsaturated groups and 2) 30 to 90weight percent (30 to 89.99 weight percent) monomers having a singleethylenically unsaturated group. In yet other embodiments, thecrosslinkable composition contains 10 to 40 weight percent polymericmaterial of Formula (II) and a second monomer composition containing 1)0.01 to 10 weight percent crosslinking monomer having at least twoethylenically unsaturated groups and 2) 50 to 90 weight percent (50 to89.99 weight percent) monomers having a single ethylenically unsaturatedgroup. The amounts are based on a total weight of polymerized andpolymerizable material in the crosslinkable composition. In a stillfurther embodiment, the crosslinkable composition contains 10 to 40weight percent polymeric material of Formula (II) and a second monomercomposition containing 1) 0.01 to 5 weight percent crosslinking monomerhaving at least two ethylenically unsaturated groups and 2) 55 to 90weight percent (55 to 89.99 weight percent) monomers having a singleethylenically unsaturated group. The amounts are based on a total weightof polymerized and polymerizable material.

In some specific embodiments, the polymeric material of Formula (II) isselected so that the final crosslinked composition is suitable for useas a pressure-sensitive adhesive composition. Although the polymericmaterial included in a pressure-sensitive adhesive can have multiplepolymeric blocks, the polymeric material often contains a singlepolymeric block. That is, the variable y in Formula (II) is equal to 1,which is equivalent to the polymeric material of Formula (II-1).

For use as a pressure-sensitive adhesive, the monomers selected to formthe polymeric material of Formula (II) are those that will result in anelastomeric material. The elastomeric material typically has a glasstransition temperature (Tg) that is no greater than 20° C., no greaterthan 10° C., no greater than 0° C., no greater than −10° C., no greaterthan −20° C., no greater than −30° C., no greater than −40° C., or nogreater than −50° C. The glass transition temperature can be measuredusing techniques such as Differential Scanning calorimetry and DynamicMechanical Analysis. Alternatively, the glass transition temperature canbe estimated using the Fox equation. Lists of glass transitiontemperatures for homopolymers are available from multiple monomersuppliers such as from BASF Corporation (Houston, Tex., USA),Polysciences, Inc. (Warrington, Pa., USA), and Aldrich (Saint Louis,Mo., USA) as well as in various publications such as, for example,Mattioni et al., J. Chem. Inf. Comput. Sci., 2002, 42, 232-240.

To form an elastomeric polymeric material of Formula (II-1), themonomeric composition 1A, which is herein also referred to as the firstmonomer composition, often contains at least one low Tg monomer. As usedherein, the term “low Tg monomer” refers to a monomer having a Tg nogreater than 20° C. when homopolymerized (i.e., a homopolymer formedfrom the low Tg monomer has a Tg no greater than 20° C.). Suitable lowTg monomers are often selected from an alkyl (meth)acrylates,heteroalkyl (meth)acrylates, aryl substituted alkyl acrylate, andaryloxy substituted alkyl acrylates.

Example low Tg alkyl (meth)acrylate monomers often are non-tertiaryalkyl acrylates but can be an alkyl methacrylates having a linear alkylgroup with at least 4 carbon atoms. Specific examples of alkyl(meth)acrylates include, but are not limited to, n-butyl acrylate,n-butyl methacrylate, isobutyl acrylate, sec-butyl acrylate, n-pentylacrylate, 2-methylbutyl acrylate, n-hexyl acrylate, cyclohexyl acrylate,4-methyl-2-pentyl acrylate, 2-methylhexyl acrylate, 2-ethylhexylacrylate, n-octyl acrylate, 2-octyl acrylate, isooctyl acrylate,isononyl acrylate, isoamyl acrylate, n-decyl acrylate, isodecylacrylate, n-decyl methacrylate, lauryl acrylate, isotridecyl acrylate,n-octadecyl acrylate, isostearyl acrylate, n-dodecyl methacrylate, anisomer of any of these monomers, or mixtures of multiple isomers.

Example low Tg heteroalkyl (meth)acrylate monomers often have aheteroalkyl group at least 3 carbon atoms, at least 4 carbon atoms, orat least 6 carbon atoms and can have up to 30 or more carbon atoms, upto 20 carbon atoms, up to 18 carbon atoms, up to 16 carbon atoms, up to12 carbon atoms, or up to 10 carbon atoms. Specific examples ofheteroalkyl (meth)acrylates include, but are not limited to,2-ethoxyethyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, 2-methoxyethyl(meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

Exemplary aryl substituted alkyl acrylates or aryloxy substituted alkylacrylates include, but are not limited to, 2-biphenylhexyl acrylate,benzyl acrylate, 2-phenoxyethyl acrylate, and 2-phenylethyl acrylate.

Monomer composition 1A (i.e. first monomer composition) used in reactionmixture 1A, which is herein also referred to as the “first reactionmixture”, for forming a polymeric material of Formula (II) oftencontains at least 40 weight percent of a low Tg monomer based on a totalweight of monomers in monomer composition 1A. In some embodiment, themonomer composition 1A contains at least 45 weight percent, at least 50weight percent, at least 60 weight percent, at least 65 weight percent,at least 70 weight percent, at least 75 weight percent, or at least 80weight percent and up to 100 weight percent, up to 99 weight percent, upto 98 weight percent, up to 95 weight percent, up to 90 weight percent,or up to 85 weight percent of the low Tg monomer.

Some monomer compositions 1A can include an optional polar monomer. Thepolar monomer has an ethylenically unsaturated group plus a polar groupsuch as an acidic group or a salt thereof, a hydroxyl group, a primaryamido group, a secondary amido group, a tertiary amido group, or anamino group. Having a polar monomer often facilitates adherence of thepressure-sensitive adhesive to a variety of substrates.

Exemplary polar monomers with an acidic group include, but are notlimited to, those selected from ethylenically unsaturated carboxylicacids, ethylenically unsaturated sulfonic acids, ethylenicallyunsaturated phosphonic acids, and mixtures thereof. Examples of suchcompounds include those selected from acrylic acid, methacrylic acid,itaconic acid, fumaric acid, crotonic acid, citraconic acid, maleicacid, oleic acid, β-carboxyethyl (meth)acrylate, 2-sulfoethylmethacrylate, styrene sulfonic acid,2-acrylamido-2-methylpropanesulfonic acid, vinyl phosphonic acid, andmixtures thereof. Due to their availability, the acid monomers are often(meth)acrylic acids.

Exemplary polar monomers with a hydroxyl group include, but are notlimited to, hydroxyalkyl (meth)acrylates (e.g., 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl(meth)acrylate, and 4-hydroxybutyl (meth)acrylate), hydroxyalkyl(meth)acrylamides (e.g., 2-hydroxyethyl (meth)acrylamide or3-hydroxypropyl (meth)acrylamide), ethoxylated hydroxyethyl(meth)acrylate (e.g., monomers commercially available from Sartomer(Exton, Pa., USA) under the trade designation CD570, CD571, and CD572),and aryloxy substituted hydroxyalkyl (meth)acrylates (e.g.,2-hydroxy-2-phenoxypropyl (meth)acrylate).

Exemplary polar monomers with a primary amido group include(meth)acrylamide. Exemplary polar monomers with secondary amido groupsinclude, but are not limited to, N-alkyl (meth)acrylamides such asN-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-isopropyl(meth)acrylamide, N-tert-octyl (meth)acrylamide, or N-octyl(meth)acrylamide.

Exemplary polar monomers with a tertiary amido group include, but arenot limited to, N-vinyl caprolactam, N-vinyl-2-pyrrolidone,(meth)acryloyl morpholine, and N,N-dialkyl (meth)acrylamides such asN,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide,N,N-dipropyl (meth)acrylamide, and N,N-dibutyl (meth)acrylamide.

Polar monomers with an amino group include various N,N-dialkylaminoalkyl(meth)acrylates and N,N-dialkylaminoalkyl (meth)acrylamides. Examplesinclude, but are not limited to, N,N-dimethyl aminoethyl (meth)acrylate,N,N-dimethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylate, N,N-dimethylaminopropyl (meth)acrylamide,N,N-diethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl(meth)acrylamide, N,N-diethylaminopropyl (meth)acrylate, andN,N-diethylaminopropyl (meth)acrylamide.

The amount of the optional polar monomer is often in a range of 0 to 30weight percent based on the weight of monomers in monomer composition 1A(i.e., first monomer composition). If present, the amounts of polarmonomers in the first monomer composition is often at least 0.1 weightpercent, at least 0.5 weight percent, or at least 1 weight percent basedon the total weight of monomers in monomer composition 1A. The amountcan be up to 30 weight percent, up to 25 weight percent, up to 20 weightpercent, up to 15 weight percent, up to 10 weight percent, or up to 5weight percent. For example, the amount is often in a range of 0 to 30weight percent, in a range of 0 to 20 weight percent, in a range of 0 to15 weight percent, in a range of 0 to 10 weight percent, in a range of 0to 5 weight percent, in a range of 0.5 to 15 weight percent, in a rangeof 1 to 15 weight percent, or in a range of 1 to 10 weight percent basedon a total weight of monomers in monomer composition 1A.

Monomer composition 1A (i.e., first monomer composition) can optionallyinclude a high Tg monomer. As used herein, the term “high Tg monomer”refers to a monomer that has a Tg greater than 30° C., greater than 40°C., or greater than 50° C. when homopolymerized (i.e., a homopolymerformed from the monomer has a Tg greater than 30° C., greater than 40°C., or greater than 50° C.). Some suitable high T_(g) monomers have asingle (meth)acryloyl group such as, for example, methyl methacrylate,ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate,n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate,tert-butyl (meth)acrylate, cyclohexyl methacrylate, isobornyl(meth)acrylate, stearyl (meth)acrylate, phenyl acrylate, benzylmethacrylate, 3,3,5 trimethylcyclohexyl (meth)acrylate, 2-phenoxyethylmethacrylate, N-octyl (meth)acrylamide, and mixtures thereof. Whilevarious vinyl monomers that do not have a (meth)acryloyl group also areclassified as high Tg monomers, they are listed separately below.

The amount of high Tg monomer used to form the polymeric material ofFormula (II) can be up to 50 weight percent or even higher provided thatthe Tg of the polymeric material is no greater than 20° C. In someembodiments, the amount can be up to 40 weight percent, up to 30 weightpercent, up to 20 weight percent, up to 15 weight percent, or up to 10weight percent. The amount can be at least 1 weight percent, at least 2weight percent, or at least 5 weight percent. For example, the amountcan be in a range of 0 to 50 weight percent, 0 to 40 weight percent, 0to 30 weight percent, 0 to 20 weight percent, 0 to 10 weight percent, 1to 30 weight percent, 1 to 20 weight percent, or 1 to 10 weight percent.The amount values are based on a total weight of monomers in monomercomposition 1A (i.e., first monomer composition).

Still further, monomer composition 1A (i.e., first monomer composition)can optionally include a vinyl monomer (i.e., a monomer with anethylenically unsaturated group that is not a (meth)acryloyl group).Examples of optional vinyl monomers include, but are not limited to,various vinyl ethers (e.g., vinyl methyl ether), vinyl esters (e.g.,vinyl acetate and vinyl propionate), styrene, substituted styrene (e.g.,α-methyl styrene), vinyl halide, and mixtures thereof. The vinylmonomers having a group characteristic of polar monomers are consideredherein to be polar monomers. The vinyl monomers often have a high Tgsuch as the (meth)acryloyl-containing high Tg monomers described above.

The amount of the optional vinyl monomer lacking a (meth)acryloyl groupis often in a range of 0 to 15 weight percent based on the weight ofmonomers in monomer composition 1A (i.e. the first monomer composition).If present, the amount of vinyl monomers in the first monomercomposition is often at least 0.1 weight percent, 0.2 weight percent,0.5 weight percent, or 1 weight percent based on the total weight ofmonomers in the first monomer composition. The amount can be up to 15weight percent, up to 10 weight percent, or up to 5 weight percent. Forexample, the amount is often in a range of 0 to 15 weight percent, in arange of 0.1 to 10 weight percent, in a range of 0.5 to 5 weightpercent, or in a range of 1 to 5 weight percent based on a total weightof monomers in the first monomer composition.

Overall the elastomeric polymeric material of Formula (II-1) can beformed from a first monomer composition that includes up to 100 weightpercent of the low Tg monomer. In some embodiments, the first monomercomposition contains 100 weight percent low Tg monomer based on thetotal weight of monomers in the first monomer composition. In otherembodiments, the first monomer composition contains 40 to 100 weightpercent of the low Tg monomer, 0 to 30 weight percent polar monomer, 0to 50 weight percent high Tg monomer, and 0 to 15 weight percent vinylmonomers not having a (meth)acryloyl group. In still other embodiments,the first monomer composition contains 60 to 100 weight percent of thelow Tg monomer, 0 to 20 weight percent polar monomer, 0 to 40 weightpercent high Tg monomer, and 0 to 10 weight percent vinyl monomers nothaving a (meth)acryloyl group. In yet other embodiments, the firstmonomer composition contains 75 to 100 weight percent of the low Tgmonomer, 0 to 10 weight percent polar monomer, 0 to 25 weight percenthigh Tg monomer, and 0 to 5 weight percent vinyl monomers not having a(meth)acryloyl group.

The resulting elastomeric polymeric material of Formula (II-1) containsup to 100 weight percent or 100 weight percent low Tg monomer units. Theweight percent value is based on the total weight of monomeric units inthe polymeric material. In some embodiments, the polymeric materialcontains 40 to 100 weight percent of the low Tg monomeric units, 0 to 15weight percent polar monomeric units, 0 to 50 weight percent high Tgmonomeric units, and 0 to 15 weight percent vinyl monomeric units. Instill other embodiments, the polymer contains 60 to 100 weight percentof the low Tg monomeric units, 0 to 10 weight percent polar monomericunits, 0 to 40 weight percent high Tg monomeric units, and 0 to 10weight percent vinyl monomeric units. In yet other embodiments, thepolymer contains 75 to 100 weight percent of the low Tg monomeric units,0 to 10 weight percent polar monomeric units, 0 to 25 weight percenthigh Tg monomeric units, and 0 to 5 weight percent monomeric units.

The weight average molecular weight of the elastomeric polymericmaterial of Formula (II-1) is often in a range of 10,000 Da to 1,000,000Da or even higher. For example, the weight average molecular weight canbe at least 20,000 Da, at least 30,000 Da, at least 40,000 Da, or atleast 50,000 and can be up to 1,000,000 Da, up to 900,000 Da, up to800,000 Da, up to 700,000 Da, or up to 600,000 Da.

The elastomeric material of Formula (II-1) can be a fully polymerizedpolymeric material (e.g., the outer blocks are greater than 99 weightpercent polymerized based on the weight of monomers used to form polymerblock P¹), a nearly fully polymerized (e.g., the outer blocks are atleast 80 to 99 weight percent polymerized polymeric material based onthe weight of the monomers used to form polymer block P¹), or arepartially polymerized (e.g., 5 to 80 weight percent polymerizedpolymeric material based on the weight of the monomers used to formpolymer block P¹). The partially polymerized polymeric materials aresyrup polymers.

Using a syrup polymer rather than a fully or nearly fully polymerizedpolymeric material can be advantageous in some embodiments. Thephotoinitiators of Formula (I) allow the formation of syrup polymersthat include polymeric chains with a narrower distribution of molecularweights compared to conventionally prepared syrup polymers. Theseconventionally prepared syrup polymers often contain a small number oflonger chains resulting in syrups with higher viscosities. That is, theviscosity of the syrup polymer can be more easily controlled andadjusted with polymeric materials formed using the photoinitiators ofFormula (I).

The elastomeric material of Formula (II-1) is combined with a secondmonomer composition containing a crosslinking monomer having at leasttwo ethylenically unsaturated groups. In some embodiments, the onlymonomer in the second monomer composition is the crosslinking monomer.In other embodiments, the second monomer composition further includes amonomer having a single ethylenically unsaturated group. The singleethylenically unsaturated monomer can be a residual monomer remaining inthe syrup polymer or can be additional monomers that were not includedin the monomer composition used to form the elastomeric material ofFormula (II-1). Examples of additional monomers are any of thosedescribed above.

In addition to the polymeric material of Formula (II) (includingelastomeric material of Formula (II-1)) and the various monomers, thecrosslinkable composition can optionally further include aphotoinitiator. The initiator can be a photoinitiator of Formula (I), aphotoinitiator not of Formula (I) such as a conventionally usedphotoinitiator for free radical polymerization reactions, or mixturesthereof. Suitable photoinitiator compounds that are not of Formula (I)include, for example, benzoin ethers (e.g., benzoin methyl ether orbenzoin isopropyl ether) or substituted benzoin ethers (e.g., anisoinether). Other exemplary photoinitiators are substituted acetophenonessuch as 2,2-diethoxyacetophenone or 2,2-dimethoxy-2-phenylacetophenone(commercially available under the trade designation IRGACURE 651 fromBASF Corp. (Florham Park, N.J., USA) or under the trade designationESACURE KB-1 from Sartomer (Exton, Pa., USA)). Still other exemplaryphotoinitiators are substituted alpha-ketols such as2-methyl-2-hydroxypropiophenone, aromatic sulfonyl chlorides such as2-naphthalenesulfonyl chloride, and photoactive oximes such as1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime. Other suitablephotoinitiators include, for example, 1-hydroxycyclohexyl phenyl ketone(commercially available under the trade designation IRGACURE 184),bis(acyl)phenyl phosphine oxides such asbis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide (commerciallyavailable under the trade designation IRGACURE 819),1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one(commercially available under the trade designation IRGACURE 2959),2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (commerciallyavailable under the trade designation IRGACURE 369),2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (commerciallyavailable under the trade designation IRGACURE 907), and2-hydroxy-2-methyl-1-phenyl propan-1-one (commercially available underthe trade designation DAROCUR 1173 from Ciba Specialty Chemicals Corp.(Tarrytown, N.Y., USA). In some embodiments, the photoinitiator is asubstituted acetophenone or a bis(acyl)phenyl phosphine oxide.

The amount of any added photoinitiator is often in a range of 0 to 1weight percent based on a total weight of polymerized and polymerizablematerial. For example, the amount can be at least 0.01 weight percent,at least 0.02 weight percent, at least 0.05 weight percent, or at least0.1 weight percent and can be up to 1 weight percent, up to 0.8 weightpercent, up to 0.5 weight percent, or up to 0.3 weight percent.

An organic solvent can be added, if desired, to control the viscosity ofthe crosslinkable composition. In many embodiments, no organic solvent(i.e., the curable composition is free of organic solvent) or only aminimum amount of the organic solvent is added. The amount of organicsolvent can be up to 60 weight percent or even higher based on a totalweight of the crosslinkable composition. The amount of organic solventcan be up to 50 weight percent, up to 40 weight percent, up to 30 weightpercent, up to 20 weight percent, up to 10 weight percent, or up to 5weight percent. In some embodiments, it is desirable to keep the contentof organic solvent as low as possible. Any organic solvent used in thesecond reaction mixture is typically removed at the completion of thecrosslinking reaction. Suitable organic solvents include, but are notlimited to, methanol, tetrahydrofuran, ethanol, isopropanol, heptane,acetone, methyl ethyl ketone, methyl acetate, ethyl acetate, toluene,xylene, and ethylene glycol alkyl ether. Those solvents can be usedalone or as mixtures thereof.

To form a crosslinked composition, the crosslinkable composition isoften applied as a layer to a substrate and then exposed to actinicradiation (e.g., ultraviolet radiation). Any suitable substrate can beused. Stated differently, an article is provided that includes a firstsubstrate and a crosslinkable composition layer positioned adjacent thefirst substrate. Any of the crosslinkable composition described abovecan be used in the crosslinkable composition layer.

The crosslinkable composition layer can be positioned adjacent to thesubstrate using any suitable process such as, for example, flow coating,dip coating, spray coating, knife coating, die coating, or extrusion.Once positioned adjacent to the substrate, the crosslinkable coatinglayer is exposed to actinic radiation (e.g., ultraviolet radiation) toreact the second monomer composition and form the crosslinkablecomposition.

The use of polymeric material of Formula (II) in the crosslinkablecomposition is particularly advantageous due to its active end groups(terminal groups). As with the formation of each block of the polymericmaterial of Formula (II), upon exposure of the crosslinkable compositionto actinic radiation (e.g., ultraviolet radiation), photolysis occursreleasing the radical of formula R¹—(CS)—S*. Monomers in thecrosslinkable composition can polymerize to form crosslinked polymericblock attached to each of the outer blocks in the polymeric material ofFormula (II). The product is a crosslinked polymeric material.

If polymeric materials are formed using conventional methods using thatlack active terminal groups (such as R¹—(CS)—S— groups in the polymericmaterials of Formula (II)) are combined with a crosslinking monomerhaving multiple ethylenically unsaturated groups, a second polymericmaterial forms that is separate from the original polymeric material.The second polymeric material is crosslinked in the presence of theoriginal polymeric material and the result is the formation of a gellednetwork. The original polymeric material is not involved in thecrosslinking reaction and usually is not covalently attached to thesecond polymeric material in the gelled network.

In contrast, the polymeric material of Formula (II) has terminalR¹—(CS)—S— groups. When exposed to actinic radiation (e.g., ultravioletradiation), radicals of formula R¹—(CS)—S* are released and the originalpolymeric material undergoes chain extension and crosslinking reactions.There is no additional second polymeric material formed that is separatefrom the original polymeric material. That is, the original polymericmaterial itself is involved in the crosslinking reaction.

The crosslinkable composition can be exposed to actinic radiation (e.g.,ultraviolet radiation) having a UVA maximum in a range of 280 to 425nanometers. Ultraviolet light sources can be of various types. Low lightintensity lights such as black lights, generally provide intensitiesranging from 0.1 or 0.5 mW/cm² (milliWatts per square centimeter) to 10mW/cm² (as measured in accordance with procedures approved by the UnitedStates National Institute of Standards and Technology as, for example,with a UVIMAP UM 365 L-S radiometer manufactured by ElectronicInstrumentation & Technology, Inc., in Sterling, Va.). High lightintensity sources generally provide intensities greater than 10, 15, or20 mW/cm² ranging up to 450 mW/cm² or greater. In some embodiments, highintensity light sources provide intensities up to 500, 600, 700, 800,900 or 1000 mW/cm². UV light to polymerize the monomer component(s) canbe provided by various light sources such as light emitting diodes(LEDs), black lights, medium pressure mercury lamps, etc. or acombination thereof. The monomer component(s) can also be polymerizedwith higher intensity light sources as available from Fusion UV SystemsInc. The UV exposure time for polymerization and curing can varydepending on the intensity of the light source(s) used. For example,complete curing with a low intensity light course can be accomplishedwith an exposure time ranging from about 30 to 300 seconds; whereascomplete curing with a high intensity light source can be accomplishedwith shorter exposure time ranging from about 5 to 20 seconds. Partialcuring with a high intensity light source can typically be accomplishedwith exposure times ranging from about 2 seconds to about 5 or 10seconds.

In some embodiments, it is preferable to use lights that emit a narrowspectrum of light in the ultraviolet region of the electromagneticspectrum. These light sources, which can include LEDs and lasers, canresult in the formation of crosslinkable compositions without the needto add conventional photoinitiators prior to the curing process. Theselight sources can enhance the rate of polymerization while maintainingthe reactive nature of the polymeric material.

In other embodiments, where broader wavelength ultraviolet light sourcesare used such as black lights, conventional photoinitiators may need tobe added to the crosslinkable compositions prior to crosslinking.

The polymeric materials of Formula (I) have dithiocarbamate ordithiocarbonate terminal groups. That is, the terminal group istypically R¹—(CS)—S—. Further, some of the crosslinked polymericmaterials may have these terminal groups If desired, this terminal groupcan be replaced after the polymeric material has formed using knownmethods such as those described, for example, in (a) Taton et al.,Handbook of RAFT Polymerization, Barner-Kowollik, ed., Wiley-VCH:Weinheim, 2008, p. 373, (b) Destarac et al., Polym. Prepr. (Am. Chem.Soc., Div. Polym. Chem.), 2008, 49(2), (c) Destarac, Polymer Preprints,2008, 49(2), page 179, and (d) Tsarevsky et al., in Controlled RadicalPolymerization: Mechanisms, ACS Symposium Series, American ChemicalSociety, Washington, D C, 2015, 211-246. Suitable methods include, forexample, converting the dithiocarbamate or dithiocarbonate functionalityinto a thiol end group through reaction with nucleophiles. The polymericmaterial with the thiol end group can undergo various radical reactions(e.g., radical catalyzed thiol-ene reactions and radical catalyzedthiol-yne reactions), nucleophilic reactions (e.g., thiol-ene Michaeladdition reactions, thiol-epoxy reactions, thiol-halide reactions,thiol-isocyanate reactions), or sulfur exchange reactions (e.g.,thiol-alkanethiosulfonate reactions and thiol-pyridyl disulfidereactions). Other example methods include free-radical reductivecleavage of the dithiocarbamate or dithiocarbonate groups, oxidationwith peroxide and ozone, and aminolysis using an amine or ammonia.

Either the polymeric material of Formula (II) or a crosslinkablecomposition that contains the polymeric material of Formula (II) can bepositioned on any suitable substrate to provide an article. Thesubstrate can be flexible or inflexible and can be formed from apolymeric material, glass or ceramic material, metal, or combinationthereof. Some substrates are polymeric films such as those prepared frompolyolefins (e.g., polyethylene, polypropylene, or copolymers thereof),polyurethanes, polyvinyl acetates, polyvinyl chlorides, polyesters(polyethylene terephthalate or polyethylene naphthalate),polycarbonates, polymethyl(meth)acrylates (PMMA), ethylene-vinyl acetatecopolymers, and cellulosic materials (e.g., cellulose acetate, cellulosetriacetate, and ethyl cellulose). Other substrates are metal foils,nonwoven materials (e.g., paper, cloth, nonwoven scrims), foams (e.g.,polyacrylic, polyethylene, polyurethane, neoprene), and the like. Forsome substrates, it may be desirable to treat the surface to improveadhesion to the polymeric material and/or to the crosslinkablecomposition and/or to the crosslinked composition. Such treatmentsinclude, for example, application of primer layers, surface modificationlayer (e.g., corona treatment or surface abrasion), or both.

In some embodiments, the substrate is a release liner. Release linerstypically have low affinity for the polymeric material, crosslinkablecomposition, and crosslinked composition. Exemplary release liners canbe prepared from paper (e.g., Kraft paper) or other types of polymericmaterial. Some release liners are coated with an outer layer of arelease agent such as a silicone-containing material or afluorocarbon-containing material.

The polymeric material or the crosslinkable composition can bepositioned next to a substrate using a roll-to-roll process. That is,the substrate can be moved from a first roll to a second roll in acontinuous process. As the substrate moves between the first roll andthe second roll, it can be coated with the polymeric material or withthe crosslinkable composition. Such a substrate can be regarded as beinga web and the web is often a polymeric material such as those describedabove. The polymeric web can be unrolled from a first roll, coated withthe crosslinkable composition, exposed to actinic radiation (e.g.,ultraviolet radiation) for crosslinking, and then rolled onto the secondroll.

The polymeric material or the crosslinkable composition coating can haveany desired thickness. The thickness of the crosslinkable compositioncoating is typically selected so that it can be effectively crosslinkedwhen exposed to actinic radiation (e.g., ultraviolet radiation). In manyembodiments, the crosslinkable composition coating has a thickness nogreater than 20 mils (500 micrometers), no greater than 10 mils (250micrometers), no greater than 5 mils (125 micrometers), no greater than4 mils (100 micrometers), no greater than 3 mils (75 micrometers), or nogreater than 2 mils (50 micrometers). The thickness is often at least0.5 mils (12.5 micrometers) or at least 1 mil (25 micrometers). Forexample, the thickness of the crosslinkable composition coating can bein the range of 0.5 mils (2.5 micrometers) to 20 mils (500 micrometers),in the range of 0.5 mils (5 micrometers) to 10 mils (250 micrometers),in the range of 0.5 mils (12.5 micrometers) to 5 mils (125 micrometers),in the range of 1 mil (25 micrometers) to 3 mils (75 micrometers), or inthe range of 1 mil (25 micrometers) to 2 mils (50 micrometers).

In some embodiments, the crosslinked composition is a pressure-sensitiveadhesive. Thus, articles with a layer of the crosslinked compositionhave a pressure-sensitive adhesive layer and can be used for manyapplications typical of such articles. The substrate adjacent to thepressure-sensitive layer can be selected depending on the specificapplication. For example, the substrate can be a sheeting material andthe resulting article can provide decorative graphics or can be areflective product. In other examples, the substrate can be label stock(the resulting article is a label with an adhesive layer), a tapebacking (the resulting article is an adhesive tape), or a foam. In yetother examples, the substrate can be a release liner and the resultingarticle can be a transfer tape. The transfer tape can be used totransfer the pressure-sensitive adhesive layer to another substrate orsurface. Other substrates and surface include, for example, a panel(e.g., a metal panel such as an automotive panel) or a glass window.

Some articles are adhesive tapes. The adhesive tapes can be single-sidedadhesive tapes with the crosslinkable composition attached to a singleside of the tape backing or can be double-sided adhesive tape with apressure-sensitive adhesive layer on both major surfaces of the tapebacking. At least one of the two pressure-sensitive adhesive layers isthe crosslinkable composition described above. Double-sided adhesivetapes are often carried on a release liner.

If desired, tackifiers can be added to the crosslinkable compositionused to form pressure-sensitive adhesives compositions. Suitabletackifying resins include rosin resins such as rosin acids and theirderivatives (e.g., rosin esters); terpene resins such as polyterpenes(e.g., alpha pinene-based resins, beta pinene-based resins, andlimonene-based resins) and aromatic-modified polyterpene resins (e.g.,phenol modified polyterpene resins); coumarone-indene resins; andpetroleum-based hydrocarbon resins such as CS-based hydrocarbon resins,C9-based hydrocarbon resins, C5/C9-based hydrocarbon resins, anddicyclopentadiene-based resins. These tackifying resins, if added, canbe hydrogenated to lower their color contribution to thepressure-sensitive adhesive composition. Combinations of varioustackifiers can be used, if desired.

Various embodiments are provided that are reaction mixtures, polymericmaterials, crosslinkable compositions, crosslinked compositions,articles containing the polymeric materials, articles containing thecrosslinkable compositions or the crosslinked compositions, methods ofmaking articles, and photoinitiators are provided.

Embodiment 1A is a first reaction mixture. The first reaction mixtureincludes a) a photoinitiator of Formula (I)

and b) a monomer composition 1A containing at least one monomer having asingle ethylenically unsaturated group. In Formula (I), group R¹ is analkoxy, aralkyloxy, alkenoxy or —N(R³)₂. Group R² is alkyl, aryl,aralkyl, or substituted aryl, wherein the substituted aryl is an arylsubstituted with at least one alkyl, alkoxy, or halo. Each R³ is analkyl or two adjacent R³ groups are combined with the nitrogen to whichthey are both attached to form a first heterocyclic ring having 1 to 3heteroatoms selected from nitrogen, oxygen, and sulfur, the firstheterocyclic ring being saturated or unsaturated and optionally fused toone or more second rings that are carbocyclic or heterocyclic.

Embodiment 2A is the first reaction mixture of embodiment 1A, whereinthe photoinitiator of Formula (I) is of Formula (I-A).

In Formula (I-A), group —OR¹⁰ is an alkyloxy, aralkyloxy, or alkenoxy(i.e., R¹⁰ is an alkyl, aralkyl, or alkenyl).

Embodiment 3A is the first reaction mixture of embodiment 1A or 2A,wherein the photoinitiator of Formula (I) is of Formula (I-C).

In Formula (I-C), group —OR¹⁰ is an alkoxy, aralkyloxy, or alkenoxy andgroup R²⁰ is an alkyl.

Embodiment 4A is the reaction mixture of embodiment 3A, wherein —OR¹⁰ isan alkoxy.

Embodiment 5A is the first reaction mixture of embodiment 1A, whereinthe photoinitiator of Formula (I) is of Formula (I-B).

In Formula (I-B), group R² is alkyl, aryl, aralkyl, or substituted aryl,wherein the substituted aryl is an aryl substituted with at least onealkyl, alkoxy, or halo. Each R³ is an alkyl or two adjacent R³ groupsare combined with the nitrogen to which they are both attached to form afirst heterocyclic ring having 1 to 3 heteroatoms selected fromnitrogen, oxygen, and sulfur, the first heterocyclic ring beingsaturated or unsaturated and optionally fused to one or more secondrings that are carbocyclic or heterocyclic.

Embodiment 6A is the first reaction mixture of embodiment 5A, wherein R³is an alkyl.

Embodiment 7A is the first reaction mixture of any one of embodiments 1Ato 6A, wherein the monomer composition 1A comprises 50 to 100 weightpercent of a first monomer with a single (meth)acryloyl group and 0 to50 weight percent of a second monomer having a single ethylenicallyunsaturated group that is not a (meth)acryloyl group. The weight percentis based on the total weight of monomers in the monomer composition 1A.

Embodiment 8A is the first reaction mixture of embodiment 7A, whereinthe monomer composition 1A comprises 80 to 100 weight percent of thefirst monomer and 0 to 20 weight percent of the second monomer.

Embodiment 9A is the first reaction mixture of any one of embodiments 1Ato 8A, wherein the first reaction mixture is free of a monomer havingmore than one ethylenically unsaturated groups.

Embodiment 1B is a second reaction mixture. The second reaction mixtureincludes a) a polymeric material of Formula (II-1)

and b) monomer composition 1B comprising at least one monomer having asingle ethylenically unsaturated group, wherein the monomer composition1B is different than a monomer composition 1A used to form a polymericmaterial of Formula (II-1). (P)₁ means that there is one polymeric blockand (P)₀₋₁ means that there are 0 to 1 polymeric blocks, each polymericblock being a polymerized product of a first monomer compositioncomprising a first monomer having a single ethylenically unsaturatedgroup. Group R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂. Group R²is alkyl, aryl, aralkyl, or substituted aryl, wherein the substitutedaryl is an aryl substituted with at least one alkyl, alkoxy, or halo.Each R³ is an alkyl or two adjacent R³ groups are combined with thenitrogen to which they are both attached to form a first heterocyclicring having 1 to 3 heteroatoms selected from nitrogen, oxygen, andsulfur, the first heterocyclic ring being saturated or unsaturated andoptionally fused to one or more second rings that are carbocyclic orheterocyclic.

Embodiment 2B is the second reaction mixture of embodiment 1B, whereinthe monomer composition 1B comprises 50 to 100 weight percent of a firstmonomer with a single (meth)acryloyl group and 0 to 50 weight percent ofa second monomer having a single ethylenically unsaturated group that isnot a (meth)acryloyl group. The weight percent is based on the totalweight of monomers in the monomer composition 1B.

Embodiment 3B is the second reaction mixture of embodiment 2B, whereinthe monomer composition 1B comprises 80 to 100 weight percent of thefirst monomer and 0 to 20 weight percent of the second monomer.

Embodiment 4B is the second reaction mixture of any one of embodiments1B to 3B, wherein the second reaction mixture is free of a monomerhaving more than one ethylenically unsaturated groups.

Embodiment 1C is a third reaction mixture. The third reaction mixtureincludes a) a polymeric material of Formula (II-2)

and b) a monomer composition 1C comprising at least one monomer having asingle ethylenically unsaturated group, wherein the monomer composition1C is different than a monomer composition 1B used to form a secondpolymeric block (an outer polymeric block, which is the block closest tothe —S—(CS)—R₁ group) of a polymeric material of Formula (II-2). InFormula (II-2), (P)₂ means that there are 2 polymeric blocks and (P)₀₋₂means that there are 0 to 2 polymeric blocks. Group R¹ is an alkoxy,aralkyloxy, alkenoxy or —N(R³)₂. Group R² is alkyl, aryl, aralkyl, orsubstituted aryl, wherein the substituted aryl is an aryl substitutedwith at least one alkyl, alkoxy, or halo. Each R³ is an alkyl or twoadjacent R³ groups are combined with the nitrogen to which they are bothattached to form a first heterocyclic ring having 1 to 3 heteroatomsselected from nitrogen, oxygen, and sulfur, the first heterocyclic ringbeing saturated or unsaturated and optionally fused to one or moresecond rings that are carbocyclic or heterocyclic.

Embodiment 2C is the third reaction mixture of embodiment 1C, whereinthe monomer composition 1C comprises 50 to 100 weight percent of a firstmonomer with a single (meth)acryloyl group and 0 to 50 weight percent ofa second monomer having a single ethylenically unsaturated group that isnot a (meth)acryloyl group. The weight percent is based on the totalweight of monomers in the monomer composition 1C.

Embodiment 3C is the third reaction mixture of embodiment 2C, whereinthe monomer composition 1C comprises 80 to 100 weight percent of thefirst monomer and 0 to 20 weight percent of the second monomer.

Embodiment 4C is the third reaction mixture of any one of embodiments 1Cto 3C, wherein the third reaction mixture is free of a monomer havingmore than one ethylenically unsaturated groups.

Embodiment 1D is a polymeric material of Formula (II).

In Formula (II), group R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂.Group R² is alkyl, aryl, aralkyl, or substituted aryl, wherein thesubstituted aryl is an aryl substituted with at least one alkyl, alkoxy,or halo. Each R³ is an alkyl or two adjacent R³ groups are combined withthe nitrogen to which they are both attached to form a firstheterocyclic ring having 1 to 3 heteroatoms selected from nitrogen,oxygen, and sulfur, the first heterocyclic ring being saturated orunsaturated and optionally fused to one or more second rings that arecarbocyclic or heterocyclic. Each P is a polymeric block that comprisesa polymerized product of a first monomer composition comprising at leastone monomer having a single ethylenically unsaturated group. Thevariables y and z refer to the number of polymeric blocks. The variabley is an integer in a range of 1 to 10, and the variable z is an integerin a range of 0 to y.

Embodiment 2D is a polymeric material of embodiment 1D, wherein thepolymeric material of Formula (II) is of Formula (II-A).

In Formula (II-A), group —OR¹⁰ is an alkyloxy, aralkyloxy, or alkenoxy(i.e., R¹⁰ is an alkyl, aralkyl, or alkenyl). Groups R² and P as well asthe variables y and z are the same as defined in Formula (II).

Embodiment 3D is the polymeric material of embodiment 1D, wherein thepolymeric material of Formula (II) is of Formula (II-B).

In Formula (II-B), groups R², R³, and P as well as the variables y and zare the same as defined in Formulas (I-B) and (II).

Embodiment 4D is the polymeric material of embodiment 1D, wherein thepolymeric material of Formula (II) is of Formula (II-C).

In Formula (II-C), group —OR¹⁰ is an alkyloxy, aralkyloxy, or alkenoxy(i.e., R¹⁰ is an alkyl, aralkyl, or alkenyl). R²⁰ is an alkyl. Groups Pas well as the variables y and z are the same as defined in Formula(II).

Embodiment 5D is the polymeric material of embodiment 1D, wherein thepolymeric material of Formula (II) is of Formula (II-1).

(P)₁ means that there is one polymeric block (the variable y is 1) and(P)_(0.1) means that there are 0 to 1 polymeric blocks (the variable zis an integer in a range of 0 to 1), each polymeric block being apolymerized product of a first monomer composition comprising a firstmonomer having a single ethylenically unsaturated group. Group R′, R²,and R³ are the same as defined for Formula (I) and Formula (II).

Embodiment 6D is the polymeric material of embodiment 5D, wherein z isequal to 1 and the polymeric material is of Formula (II-1A).

P¹ refers to a first polymeric block.

Embodiment 7D is the polymeric material of embodiment 1D, wherein thepolymeric material of Formula (II) is of Formula (II-2).

In Formula (II-2), (P)₂ means that there are 2 polymeric blocks (thevariable y is 2) and (P)₀₋₂ means that there are 0 to 2 polymeric blocks(the variable z is an integer in a range of 0 to 2). Each polymericblock being a polymerized product of a first monomer compositioncomprising a first monomer having a single ethylenically unsaturatedgroup. Group R′, R², and R³ are the same as defined for Formula (I) andFormula (II).

Embodiment 8D is the polymeric material of embodiment 7D, wherein z isequal to 2 and the polymeric material is of Formula (II-2A).

P¹ refers to the first polymeric block and P² refers to the secondpolymeric block.

Embodiment 9D is the polymeric material of embodiment 1D, wherein thepolymeric material of Formula (II) is of Formula (II-3).

In Formula (II-3), (P)₃ means that there are 3 polymeric blocks (thevariable y is 3) and (P)₀₋₃ means that there are 0 to 3 polymeric blocks(the variable z is an integer in a range of 0 to 3). Each polymericblock being a polymerized product of a first monomer compositioncomprising a first monomer having a single ethylenically unsaturatedgroup. Group R¹, R², and R³ are the same as defined for Formula (I) andFormula (II).

Embodiment 10D is the polymeric material of embodiment 9D, wherein z isequal to 3 and the polymeric material is of Formula (II-3A).

P¹ refers to the first polymeric block, P² refers to the secondpolymeric block, and P³ refers to the third polymeric block.

Embodiment 1E is a crosslinkable composition is provided that containsa) a polymeric material of Formula (II)

and b) a second monomer composition comprising a crosslinking monomerhaving at least two ethylenically unsaturated groups. In Formula (II),group R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂. Group R² isalkyl, aryl, aralkyl, or substituted aryl, wherein the substituted arylis an aryl substituted with at least one alkyl, alkoxy, or halo. Each R³is an alkyl or two adjacent R³ groups are combined with the nitrogen towhich they are both attached to form a first heterocyclic ring having 1to 3 heteroatoms selected from nitrogen, oxygen, and sulfur, the firstheterocyclic ring being saturated or unsaturated and optionally fused toone or more second rings that are carbocyclic or heterocyclic. Each P isa polymeric block that comprises a polymerized product of a firstmonomer composition comprising at least one monomer having a singleethylenically unsaturated group. The variables y and z refer to thenumber of polymeric blocks. The variable y is an integer in a range of 1to 10, and the variable z is an integer in a range of 0 to y.

Embodiment 2E is the crosslinkable composition of embodiment 1E, whereinthe polymeric material is according to any one of embodiment 2D to 6D.

Embodiment 3E is the crosslinkable composition of embodiment 1E or 2E,wherein the polymeric material of Formula (II) (such as Formula (II-1))is an elastomeric material.

Embodiment 4E is the crosslinkable composition of any one of embodiments1E to 3E, wherein the second monomer composition further comprises amonomer having a single ethylenically unsaturated group.

Embodiment 5E is the crosslinkable composition of any one of embodiments1E to 4E, wherein the crosslinkable composition comprises 1) 5 to 99.99weight percent polymeric material of Formula (II) and 2) a secondmonomer composition comprising a) 0.01 to 20 weight percent crosslinkingmonomer having at least two ethylenically unsaturated groups, and b) 0to 95 weight percent monomer having a single ethylenically unsaturatedgroup, wherein each amount is based on a total weight of polymerized andpolymerizable material.

Embodiment 6E is the crosslinkable composition of any one of embodiments1E to 5E, wherein the crosslinkable composition comprises 1) 10 to 60weight percent polymeric material of Formula (II) and 2) a secondmonomer composition comprising a) 0.01 to 10 weight percent crosslinkingmonomer having at least two ethylenically unsaturated groups, and b) 30to 90 weight percent monomer having a single ethylenically unsaturatedgroup, wherein each amount is based on a total weight of polymerized andpolymerizable material.

Embodiment 7E is the crosslinkable composition of any one of embodiments1E to 6E, wherein the crosslinkable composition comprises 1) 10 to 40weight percent polymeric material of Formula (II) and 2) a secondmonomer composition comprising a) 0.01 to 5 weight percent crosslinkingmonomer having at least two ethylenically unsaturated groups, and b) 55to 90 weight percent monomer having a single ethylenically unsaturatedgroup, wherein each amount is based on a total weight of polymerized andpolymerizable material.

Embodiment 8E is the crosslinkable composition of any one of embodiments2E to 7E, wherein the polymeric material of Formula (II) is of Formula(II-1) and is a reaction product of first monomer composition comprising40 to 100 weight percent of a low Tg monomeric unit, 0 to 15 weightpercent of a polar monomeric unit, 0 to 50 weight percent of a high Tgmonomeric unit (i.e., a high Tg (meth)acryloyl-containing monomericunit), and 0 to 15 weight percent vinyl monomeric units based on a totalweight of monomeric units.

Embodiment 9E is the crosslinkable composition of any one of embodiments1E to 8E, wherein the polymeric material of Formula (II) has a weightaverage molecular weight in a range of 10,000 Daltons to 5 millionDaltons.

Embodiment 10E is the crosslinkable composition of any one ofembodiments 1E to 9E, wherein the crosslinkable composition furthercomprises a photoinitiator.

Embodiment 11E is the crosslinkable composition of embodiment 10E,wherein the photoinitiator is of Formula (I).

In Formula (I), group R¹, R², and R³ are the same as in Formula (II).

Embodiment 12E is the crosslinkable composition of embodiment 10E,wherein the photoinitiator is not of Formula (I).

Embodiment 13E is the crosslinkable composition of any one ofembodiments 1E to 12E, wherein the crosslinkable composition furthercomprises a tackifier.

Embodiment 1F is a crosslinked composition that includes a cured productof a crosslinkable composition. The crosslinkable composition isaccording to embodiment 1E.

Embodiment 2F is the crosslinked composition of embodiment 1F, whereinthe crosslinkable composition is according to any one of embodiments 2Eto 13E.

Embodiment 3F is the crosslinked composition of embodiment 1F or 2F,wherein the crosslinked composition is a pressure-sensitive adhesive.

Embodiment 1G is an article that includes a first substrate and acrosslinkable composition layer adjacent to the substrate, wherein thecrosslinkable composition is of embodiment 1E.

Embodiment 2G is the article of embodiment 1G, wherein the crosslinkablecomposition is according to any one of embodiments 2E to 13E.

Embodiment 1H is an article that includes a first substrate and acrosslinked composition layer adjacent to the substrate, wherein thecrosslinked composition layer includes a cured product of acrosslinkable composition of embodiment 1E.

Embodiment 2H is the article of embodiment 1H, wherein the crosslinkablecomposition is according to any one of embodiments 2E to 13E.

Embodiment 1I is a method of making an article. The method includesproviding a first substrate and applying a layer of a crosslinkablecomposition adjacent to the first substrate. The crosslinkablecomposition is of any one of embodiments 1E to 13E. The method furtherincludes exposing the layer of crosslinkable composition to actinicradiation to form a layer of crosslinked composition. The actinicradiation includes actinic radiation.

Embodiment 2I is the method of embodiment 1I, wherein the substrate isin the form of a polymeric web.

Embodiment 3I is the method of embodiment 1I or 2I, wherein the actinicradiation is from a light emitting diode.

Embodiment 1J is an article that includes a first substrate and a layercontaining the polymeric material of Formula (II) as described in anyone of embodiments 1D to 6D.

Embodiment 1K is a method of making a polymeric material. The methodincludes providing a photoinitiator of Formula (I).

In Formula (I), group R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂.Group R² is alkyl, aryl, aralkyl, or substituted aryl, wherein thesubstituted aryl is an aryl substituted with at least one alkyl, alkoxy,or halo. Each R³ is an alkyl or two adjacent R³ groups are combined withthe nitrogen to which they are both attached to form a firstheterocyclic ring having 1 to 3 heteroatoms selected from nitrogen,oxygen, and sulfur, the first heterocyclic ring being saturated orunsaturated and optionally fused to one or more second rings that arecarbocyclic or heterocyclic. The method further includes preparing afirst reaction mixture comprising the photoinitiator of Formula (I) anda first monomer composition comprising at least one monomer having asingle ethylenically unsaturated group. The method still furtherincludes forming a first polymeric material of Formula (II-1) from thefirst reaction mixture.

(P)₁ means that there is one polymeric block and (P)₀₋₁ means that thereare zero or one polymeric blocks. Each polymeric block is a polymerizedproduct of a first monomer composition.

Embodiment 1L is a compound of Formula (I-B) that can function as aphotoinitiator.

In Formula (I-B), group R² is alkyl, aryl, aralkyl, or substituted aryl,wherein the substituted aryl is an aryl substituted with at least onealkyl, alkoxy, or halo. Each R³ is an alkyl or two adjacent R³ groupsare combined with the nitrogen to which they are both attached to form afirst heterocyclic ring having 1 to 3 heteroatoms selected fromnitrogen, oxygen, and sulfur, the first heterocyclic ring beingsaturated or unsaturated and optionally fused to one or more secondrings that are carbocyclic or heterocyclic.

Embodiment 1M is a compound of Formula (I-C) that can function as aphotoinitiator.

In Formula (I-C), group —OR¹⁰ is an alkoxy, aralkyloxy, or alkenoxy andGroup R²⁰ is an alkyl.

EXAMPLES Test Methods Peel Adhesion Strength

Stainless steel (SS) panels were cleaned by wiping them three timesusing methyl ethyl ketone and a clean lint-free tissue. The cleanedpanels were allowed to dry at room temperature. Tape samples measuring0.5 inch (1.27 centimeters) wide and 8 inches (20.3 centimeters) longwere cut, then centered on the cleaned panels and adhered to one endsuch that tape overlapped the panel by 25.4 millimeters (1 inch) in thelengthwise direction. The tape sample was then rolled down one time ineach direction using a 4.5 pound (about 2 kilograms) rubber roller.After conditioning for 15 minutes at 23° C. (73° F.) and 50% relativehumidity (RH), the peel adhesion strength was measured, under the sametemperature and relative humidity as used above, at an angle of 180degrees and a rate of 305 millimeters/minute (12 inches/minute) using apeel adhesion tester (IMASS Slip/Peel Tester, Model SP-2000, availablefrom IMASS Incorporated, Accord, Mass.). Four samples were evaluated,the results normalized to ounces/inch (oz/in) and the average valuecalculated. The results were reported in both ounces/inch (oz/in) andNewtons/decimeter (N/dm).

Shear Adhesion Strength—Elevated Temperature

Stainless steel (SS) panels were cleaned by wiping them three timesusing methyl ethyl ketone and a clean lint-free tissue. Tape samplesmeasuring 0.5 inch (1.27 centimeters) wide and between 3 and 4 inches(7.6 and 10.2 centimeters) long were cut, then centered on the cleanedpanels and adhered to one end such that tape overlapped the panel by25.4 millimeters (1 inch) in the lengthwise direction. The tape samplewas then rolled down one time in each direction using a 4.5 pound (ca. 2kilograms) rubber roller. After conditioning the tape/test panelassembly for 15 minutes at 23° C. (73° F.) it was suspended in a standin an oven heated to 158° F. (70° C.) and tilted at an angle of 2° fromvertical to ensure a shear force. A 500 gram weight was hung from thefree end of the tape sample. The time, in minutes, for the tape to fallfrom the panel was recorded. The test was terminated if failure had notoccurred in 10,000 minutes and the result recorded as “10,000+”. Onetest sample was run for each tape construction.

Molecular Weight by Gel Permeation Chromatography (GPC)

Molecular weights and polydispersity were determined at 23° C. by gelpermeation chromatography (GPC) using a Waters LC SYSTEM (WatersCorporation, Milford, Mass.) equipped with a Waters STYRAGEL HR 5E THF300 millimeter (length)×7.8 millimeter I.D. (Inside Diameter) column, incombination with a Waters 2414 REFRACTIVE INDEX DETECTOR. Samplesolutions were prepared by adding 10 milliliters of tetrahydrofuran(THF) to a sample weighing between approximately 50 and 100 milligramsand mixing for at least one hour followed by filtering through a 0.2micrometer polytetrafluoroethylene syringe filter. The injection volumewas 20 microliters and the THF eluent flow rate was 1.0milliliter/minute. Weight and Number Average Molecular Weights (Mw andMn, grams/mole (Daltons or Da)) and polydispersity index, PDI (Mw/Mn)were determined relative to a calibration curve with polystyrenestandards.

Sodium Isopropyl Xanthate

In a flask equipped with a mechanical stirrer, isopropanol (871.10grams, 14.49 moles) was bubbled with nitrogen. Sodium metal cubes (20.25grams, 0.88 moles, Sigma-Aldrich Corporation, Milwaukee, Wis.) were cutinto small pieces and added to the flask over 3 hours. The temperaturewas then increased to 65° C. The sodium dissolved with evolution ofhydrogen over 3 additional hours resulting in a clear solution. Themixture was cooled to 35° C. using an ice bath, which resulted in athick slurry. Carbon disulfide (73.80 grams, 0.97 moles) was then addedslowly over 30 minutes. After full addition, the mixture was stirred foran additional 30 minutes resulting in a yellow solution. Solvent wasremoved by placing the mixture under vacuum resulting in a yellow solid.The product was further dried under high vacuum (1 millimeter Hg) for 4hours resulting in a yellow powder (136.67 grams).

Preparation of O-Isopropyl-S-acetonyl-dithiocarbonate (PI-1)

A mixture of sodium isopropyl xanthate (5.00 grams, 32 millimoles) andacetone (35 milliliters) was cooled using an ice bath. A solution of1-chloropropan-2-one (2.59 grams, 28 millimoles, TCI America, Portland,Oreg.) in acetone (5 milliliters) was added slowly over 5 minutes. Afterstirring at room temperature for 2 hours, the solvent was removed undervacuum. Ethyl acetate (30 milliliters) was added and the mixture waswashed with water. The organic phase was concentrated under vacuum andthe residual oil was purified by column chromatography over silica gel(2 to 20% ethyl acetate in hexanes). A yellow oil was isolated (4.95grams).

Preparation of O-Ethyl-S-phenacyl dithiocarbonate (PI-2)

A mixture of potassium ethyl xanthate (6.22 grams, 39 millimoles, AlfaAesar, Ward Hill, Mass.) and acetone (30 milliliters) was cooled usingan ice bath. A solution of 2-chloro-1-phenyl-ethanone (5.00 grams, 32millimoles, TCI America) in acetone (15 milliliters) was added slowlyover 15 minutes. After stirring at room temperature for 1 hour, thesolvent was removed under vacuum. Ethyl acetate (60 milliliters) wasadded and the mixture was washed with water two times. The organic phasewas concentrated under vacuum and the residual oil was purified bycolumn chromatography over silica gel (1 to 15% ethyl acetate inhexanes). A slightly yellow solid was isolated (6.04 grams).

Preparation of Carbonodithioic acid, O-isopropyl S-(3-pentane-2-4-dione)ester (PI-3)

A mixture of sodium isopropyl xanthate (4.23 grams, 27 millimoles) andacetone (50 milliliters) was cooled using an ice bath. A solution of3-chloropentane-2,4-dione (3.00 grams, 22 millimoles, Alfa Aesar) inacetone (5 milliliters) was added slowly over 5 minutes. After stirringat room temperature for 3 hours, the solvent was removed under vacuum.Ethyl acetate (30 milliliters) was added and the mixture was washed withwater. The organic phase was concentrated under vacuum and the residualoil was purified by column chromatography over silica gel (1 to 10%ethyl acetate in hexanes). A yellow solid was isolated (4.30 grams).

Preparation of 1,1-bis(isopropoxycarbothioylsulfanyl)-2-propanone (PI-4)

A mixture of sodium isopropyl xanthate (6.86 grams, 43 millimoles) andacetone (40 milliliters) was cooled using an ice bath. A solution of1,1-dichloropropan-2-one (2.50 grams, 20 millimoles, Alfa Aesar) inacetone (5 milliliters) was added slowly over 5 minutes. After stirringat room temperature for 3 hours, the solvent was removed under vacuum.Ethyl acetate (30 milliliters) was added and the mixture was washed withwater two times. The organic phase was concentrated under vacuum and theresidual oil was purified by column chromatography over silica gel (1 to10% ethyl acetate in hexanes). A yellow oil was isolated (4.73 grams).

Preparation of 2,2-bis(isopropoxycarbothioylsulfanyl)-1-phenyl ethanone(PI-5)

A mixture of sodium isopropyl xanthate (10.46 grams, 66 millimoles) andacetone (50 milliliters) was cooled using an ice bath. A solution of2,2-dichloro-1-phenyl-ethanone (5.00 grams, 26 millimoles, Alfa Aesar)in acetone (15 milliliters) was added slowly over 15 minutes. Afterstirring at room temperature for 3 hours, the solvent was removed undervacuum. Ethyl acetate (60 milliliters) was added and the mixture waswashed with water two times. The organic phase was concentrated undervacuum and the residual oil was purified by column chromatography oversilica gel (1 to 15% ethyl acetate in hexanes). The recovered solidproduct was recrystallized from heptane to give a yellow solid (8.36grams).

Preparation of 2,2-bis(isopropoxycarbothioylsulfanyl)-1-(4-bromophenyl)ethanone (PI-6)

A mixture of sodium isopropyl xanthate (6.83 grams, 43 millimoles) andacetone (40 milliliters) was cooled using an ice bath. A solution of2,2-dibromo-1-(4-bromophenyl)ethanone (7.00 grams, 20 millimoles, AlfaAesar) in acetone (15 milliliters) was added slowly over 15 minutes.After stirring at room temperature for 4 hours, the solvent was removedunder vacuum. Ethyl acetate (30 milliliters) was added and the mixturewas washed with water two times. The organic phase was concentratedunder vacuum and the recovered solid product was recrystallized fromheptane two times to give a yellow solid (4.90 grams).

Preparation of 1,1-bis(diethylcarbamothioylsulfanyl)-1-phenyl ethenone(PI-7)

A mixture of sodium diethyldithiocarbamate trihydrate (13.52 grams, 60millimoles, Alfa Aesar, Ward Hill, Mass.) and acetone (40 milliliters)was cooled using an ice bath. A solution of2,2-dichloro-1-phenyl-ethanone (5.00 grams, 27 millimoles, TCI America)in acetone (5 milliliters) was added slowly over 5 minutes. Afterstirring at room temperature for three hours, the solvent was removedunder vacuum. Ethyl acetate (30 milliliters) was added and the mixturewas washed with water. The organic phase was concentrated under vacuumand the crude solid was recrystallized from a mixture of heptane andethyl acetate. A slightly yellow solid was isolated (10.09 grams).

Preparation of 1,1-bis(diethylcarbamothioylsulfanyl)-2-propanone (PI-8)

A mixture of sodium diethyldithiocarbamate trihydrate (9.37 grams, 42millimoles, Alfa Aesar) and acetone (40 milliliters) was cooled using anice bath. A solution of 1,1-dichloropropan-2-one (2.50 grams, 20millimoles, Alfa Aesar) in acetone (5 milliliters) was added slowly over5 minutes. After stirring at room temperature for three hours, thesolvent was removed under vacuum. Ethyl acetate (30 milliliters) wasadded and the mixture was washed with water. The organic phase wasconcentrated under vacuum. A yellow solid was isolated (5.92 grams).

Preparation of Polymers Examples 1-11 and Comparative Examples 1-3

Polymers of 2-ethylhexyl acrylate (2EHA) were prepared usingPhotoinitiators 1-6 (PI 1-6) using the materials and amounts shown inTable 1 below as follows. A solution of 2-ethylhexyl acrylate (2EHA,available from BASF Corporation, Charlotte, N.C.), photoinitiator, andethyl acetate was placed in a 250 milliliter, 2-necked round bottomflask and degassed with a nitrogen stream for 15 minutes. The flask wasthen held under a positive pressure of nitrogen, stirred magnetically,and irradiated with light emitting diodes (LED) using a 365 nanometerLED array (Model LED365-0556 LED Bank, Clearstone Technologies,Incorporated, Hopkins, Minn.) at a power setting of 15% and a distanceof 3 inches from the flask edge. The total energy provided after anexposure time of 5 minutes was 1850 milliJoules/square centimeters atthe surface of the solution. Samples were removed at intervalsthroughout the polymerization and molecular weights were determined bygel permeation chromatography (GPC). Monomer conversion (mole %) wasdetermined by proton NMR analysis in deuterated chloroform using thefollowing procedure. The 2EHA monomer conversion was calculated as theamount of poly(2EHA) (integral of resonance at 3.94 ppm divided by 2)divided by the sum of poly(2EHA) and unreacted monomer 2EHA (integral ofresonance at 5.80 ppm), with the resulting value multiplied by 100.

TABLE 1 Compositions Photoinitiator 2EHA Ethyl acetate ExamplePhotoinitiator (grams) (grams) (grams) C1 PI-1 0.150 25.033 25.095 C2PI-2 0.109 25.141 25.035 C3 PI-3 0.108 25.005 25.040   1 PI-4 0.10425.017 25.010   2 PI-5 0.105 25.062 25.020   3 PI-6 0.101 25.012 25.002

TABLE 2 Results for 2EHA and PI-1 Irradiation 2EHA Time Conversion Mn MwExample (minutes) (mole %) (Da) (Da) PDI C1-1 15.0 15.0 252528 3999621.58 C1-2 26.5 26.5 207418 351508 1.69 C1-3 36.6 36.6 169742 311676 1.84C1-4 53.4 53.4 148023 270297 1.83 C1-5 63.1 63.1 131128 256209 1.95 C1-674.9 74.9 112923 245061 2.17 C1-7 83.3 83.3 91688 219013 2.39 C1-8 88.588.5 83907 219383 2.61 C: Comparative Example

TABLE 3 Results for 2EHA and PI-2 Irradiation 2EHA Time Conversion Mn MwExample (minutes) (mole %) (Da) (Da) PDI C2-1 1.0 19.0 96510 156506 1.62C2-2 2.0 33.6 81569 139026 1.70 C2-3 3.0 44.7 72303 131692 1.82 C2-4 4.053.6 66290 125152 1.89 C2-5 6.5 66.1 61701 120420 1.95 C2-6 9.0 74.459966 119895 2.00 C2-7 16.0 84.4 55109 115793 2.10 C2-8 34.5 92.0 50088111929 2.23 C: Comparative Example

TABLE 4 Results for 2EHA and PI-3 Irradiation 2EHA Time Conversion Mn MwExample (minutes) (mole %) (Da) (Da) PDI C3-1 7.5 14.8 523311 8446521.61 C3-2 16.5 26.6 458409 812095 1.78 C3-3 29.5 39.0 496225 942781 1.90C3-4 53.5 58.8 403297 763042 1.89 C: Comparative Example

TABLE 5 Results for 2EHA and PI-4 Irradiation 2EHA Time Conversion Mn MwExample (minutes) (mole %) (Da) (Da) PDI 1-1 3.0 6.2 12756 19472 1.531-2 7.0 19.6 19205 35941 1.87 1-3 9.0 34.5 28294 59005 2.09 1-4 10.545.0 36130 73334 2.03 1-5 13.0 59.4 43019 86245 2.00 1-6 16.0 71.3 4979894454 1.90 1-7 25.5 84.1 53397 101272 1.90 1-8 35.5 89.1 54437 1030761.89

TABLE 6 Results for 2EHA and PI-5 Irradiation 2EHA Time Conversion Mn MwExample (minutes) (mole %) (Da) (Da) PDI 2-1 4.0 11.2 16123 28546 1.772-2 7.0 25.8 24918 53483 2.15 2-3 9.0 40.2 37162 78126 2.13 2-4 11.553.5 45903 96859 2.11 2-5 14.0 64.7 52903 104834 1.89 2-6 18.5 74.859965 113570 1.89 2-7 24.0 82.2 63143 120903 1.91 2-8 34.5 87.9 65651124090 1.89

TABLE 7 Results for 2EHA and PI-6 Irradiation 2EHA Time Conversion Mn MwExample (minutes) (mole %) (Da) (Da) PDI 3-1 6.5 26.9 33548 65579 1.953-2 8.5 42.8 42899 90850 2.12 3-3 10.5 56.1 52163 103890 1.99 3-4 13.568.1 58020 114953 1.98 3-5 18.5 77.2 60742 120495 1.98 3-6 26.5 84.764916 128820 1.98 3-7 38.0 89.2 68165 129809 1.90

Example 4 and Comparative Example 4

Copolymers of the 2EHA polymers Comparative Example 2-8 and Example 3-7,prepared as described above, and isobutyl acrylate (IBA) were preparedusing the materials and amounts shown in Table 8 below as follows.Isobutyl acrylate (2.50 grams, IBA, Alfa Aesar) and ethyl acetate (2.50grams) were added to the final poly(2EHA) solution from ComparativeExample 2 (C2-8) and Example 3 (3-7), and (5.00 grams of each solution)in vials. The solutions were purged with dry nitrogen for 10 minutes andthe vials capped. The vials were then rolled and irradiated with lightemitting diodes (LED) using a 365 nanometer LED array (Model LED365-0556LED Bank, Clearstone Technologies, Incorporated) at a power setting of15% and at a distance of 3 inches from the top of the vials. The totalenergy provided after an exposure time of 1 minute was 793milliJoules/square centimeters at the top of the vial. After a total of45 minutes of LED exposure, the mixtures were evaluated for molecularweight by gel permeation chromatography (GPC). The total monomerconversion (mole %) was determined from NMR analysis using thefollowing:

-   -   A: amount of poly-2EHA-IBA plus unreacted monomer (2EHA and        IBA)=(integral of resonances at 3.65 ppm to 4.09 ppm)    -   B: amount of unreacted monomer 2EHA and IBA=(integral of        resonance at 5.76 ppm)

Total conversion=100*((A−(2*B))/A).

TABLE 8 Compositions and Results for 2EHA Polymer and IBA Total InitialAcrylate Molecular Weights 2EHA (2EHA & BA) Initial 2EHA Polymer Final2EHA/IBA Copolymer Polymer Conversion Mn Mw Mn Mw Ex. Solution (mole %)(Da) (Da) PDI (Da) (Da) PDI C4   C2-8 87 50088 111929 2.23 45098 942972.09 4   3-7 81 68165 129809 1.90 80384 171062 2.13 C: ComparativeExample

Examples 5-8 and Comparative Example 5

Polymers of butyl acrylate (BA) were prepared using Photoinitiators 1and 5-8 (PI-1 and PI-5 to PI-8) using the materials and amounts shown inTable 9 below as follows. A stock solution of butyl acrylate (BA, 20.00grams, Alfa Aesar) and ethyl acetate (20.00 grams) was prepared. Thephotoinitiator (0.011 grams) and butyl acrylate stock solution (5.00grams) were mixed in vials. The solutions were purged with dry nitrogenfor 1 minute and the vials capped. The vials were then rolled andirradiated under a UV lamp (OSRAM SYLVANIA F15T8/BLB Blacklight Blue,peak wavelength of 362 nanometers) placed 13 centimeters above thevials. The total energy provided after an exposure time of 30 minuteswas 0.04 milliJoules/square centimeters at the top of the vial. After UVexposure, the mixtures were evaluated for molecular weight by gelpermeation chromatography (GPC). Monomer conversion (mole %) wasdetermined by proton NMR analysis in deuterated chloroform using thefollowing procedure. The BA conversion was calculated as the amount ofpoly(BA) (integral of resonance at 4.03 ppm divided by 2) divided by thesum of poly(BA) and unreacted monomer BA (integral of resonance at 6.40ppm), with the resulting value multiplied by 100.

TABLE 9 Compositions and Results for BA Polymer Irradiation BA TimeConversion Mn Mw Example Photoinitiator (hours) (mole %) (Da) (Da) PDIC5   PI-1 1.5 66 187390 429222 2.29 5 PI-5 1.5 85 67895 129437 1.91 6PI-6 1.5 84 74450 141300 1.90 7 PI-7 14 84 87495 147864 1.69 8 PI-8 1482 78645 128100 1.63

Examples 9 and 10 and Comparative Example 6

Copolymers of the BA polymers Comparative Example 5 and Examples 5 and6, prepared as described above, and isobornyl acrylate (IBOA) wereprepared using the materials and amounts shown in Table 10 below asfollows. To vials were added isobornyl acrylate (2.50 grams, IBOA, AlfaAesar) and ethyl acetate (2.50 grams) and the final poly(BA) solutionsfrom Comparative Example 5 and Examples 5 and 6. The solutions werepurged with dry nitrogen for 1 minute and the vials capped. The vialswere then rolled and irradiated under a UV lamp (OSRAM SYLVANIAF15T8/BLB Blacklight Blue, peak wavelength of 362 nanometers) placed 13centimeters above the vials. The total energy provided after an exposuretime of 30 minutes was 0.04 milliJoules/square centimeters at the top ofthe vials. After UV exposure for 3 hours, the mixtures were evaluatedfor molecular weight by gel permeation chromatography (GPC). Monomerconversion (mole %) was determined by proton NMR analysis in deuteratedchloroform using the following procedure. The BA conversion wascalculated as the amount of poly(BA) (integral of resonance at 4.03 ppmdivided by 2) divided by the sum of poly(BA) and unreacted monomer BA(integral of resonance at 6.40 ppm), with the resulting value multipliedby 100. The IBOA conversion was calculated as the amount of poly(IBOA)(integral of resonance at 4.58 ppm divided by the sum of poly(IBOA) andunreacted monomer IBOA (integral of resonance at 4.71 ppm), with theresulting value multiplied by 100.

TABLE 10 Compositions and Results for BA Polymer and IBOA MolecularWeights Initial BA Total BA Total IBOA Initial 2BA Polymer Final BA/IBOACopolymer Polymer Conversion Conversion Mn Mw Mn Mw Ex. Solution (mole%) (mole %) (Da) (Da) PDI (Da) (Da) PDI C6  C5   81 50 187390 4292222.29 199803 466950 2.34  9 5 87 34 67895 129437 1.91 88631 204465 2.3110 6 91 54 74450 141300 1.90 100680 248283 2.47 C: Comparative Example

Example 11

Polymers of butyl acrylate (BA) were prepared using Photoinitiator 5(PI-5) as follows. A solution was prepared containing 20.0 grams ofbutyl acrylate (BA) and 0.23 grams of PI-5. Aliquots of approximately 1gram of this solution were added to individual vials, purged withnitrogen for two minutes, and then sealed. The vials were irradiatedwith a UV lamp (OSRAM SYLVANIA F15T8/BLB Blacklight Blue, peakwavelength of 362 nanometers) placed 12.7 centimeters above the vials.The total energy provided after an exposure time of 30 minutes was 0.04milliJoules/square centimeters at the top of the vials. The vials wereremoved from the light at various time intervals and evaluated formonomer conversion (gravimetrically and by NMR), molecular weights (byGPC and NMR), as well as fraction of free initiator, and fraction ofmono-directional polymer chains (by NMR). The gravimetric weight percent(wt %) conversion of monomer was determined by recording the weight ofthe sample, heating the sample at 120° C. for two hours, and thenmeasuring the final weight. The wt % conversion was calculated asfollows.

Wt % Conversion=final weight/initial weight)×100

NMR analysis was carried out as follows. Approximately 50-100 milligramsof each polymer sample was dissolved in approximately 1 milliliter ofdeuterated chloroform and NMR spectra were acquired on a Bruker AVANCEIII 500 MHz spectrometer equipped with a broadband cryoprobe. Spectrawere acquired with a low tip angle (15) and a relaxation delay of 4seconds for good quantitation. Two-dimensional (2D) NMR experiments(gCOSY, TOCSY, gHSQC, and gHMBC) were acquired to assign the freeinitiator and different polymer end groups. As the polymerizationprogressed, two different type of polymeric chains were observed asdepicted in the schematic below.

FIG. 1 shows the aromatic region of the ¹H NMR spectrum for 6%conversion (i.e. polymerization) of the monomers. The peak assignmentswere confirmed from a 2D gHMBC experiment. The free initiator has asharp singlet for the methine proton between two sulfurs at 7.09 ppm.The methine sulfur of the phenyl initiator fragment of themono-directional polymer chain is shifted upfield to 5.46 ppm. The gHMBCcorrelations from this resonance to the phenyl carbonyl at 195 ppm andxanthate thiocarbonyl at 211 ppm confirm the assignment. As used herein,the term “mono-directional” refers to polymeric chains where a singleradical group of formula R₃—(CS)—S* has been cleaved to initiatepolymeric chain growth in a single direction. The bi-directional polymerchain has only the phenyl ketone group in the core, which has resonancesbetween 7.85-8.00 ppm that correlate to a novel carbonyl frequency at202 ppm. As used herein, the term “bi-directional” refers to polymericchains where two radical groups of formula R₃-(CS)—S* (which in thisexample are both the xanthate groups iso-C₃H₇O—(CS)—S*) have beencleaved to initiate polymeric chain growth in two directions and theresulting initiator fragment *—CH(C═O-Ph)* is left in the middle of thepolymer chain.

A variety of parameters were determined from the integrals in the ¹H NMRspectra, including percent conversion, the number average molecularweight (M₁₁), the mole fraction of free initiator remaining, and themole fraction of polymeric chains that are mono-directional. Percentconversion was calculated as the amount of poly(BA) (integral ofresonance at 4.03 ppm divided by 2) divided by the sum of poly(BA) andunreacted monomer BA (integral of resonance at 6.40 ppm) multiplied by100. The degree of polymerization (DP) was determined from the moles ofpolymer repeat unit (integral at 4.03 ppm divided by 2) divided by themoles of polymer chains. According to the reaction scheme above, thereis one mono-directional or one bi-directional phenyl group per polymerchain. The relative moles of each polymer chain type was calculated asfollows. The moles of mono-direction polymer chains were determined fromthe resolved methine S—CH resonance at 5.46 ppm (divided by 1). Theproton resonances of the bi-directional aromatic group partially overlapwith the phenyl group of the mono-directional chain and free initiator.However, the bi-directional integrals can be determined by subtractionof the relative molar amounts from other resolved resonances of the freeinitiator and mono-directional chain. The total integral between7.85-8.20 ppm is the two phenyl protons adjacent to the ketone for allphenyl species. From this integral the value of 2 times the freeinitiator integral at 7.09 ppm and 2 times the mono-directional integralat 5.46 ppm was subtracted to determine the remaining bi-directionalphenyl integral. The remaining integral was divided by 2 to determinethe moles of bi-directional polymer chains. From the calculated DP, thenumber average molecular weight (Mn) was calculated as DP*128.17 (themolecular weight of a BA repeat unit). The mole fraction of freeinitiator remaining was calculated from the moles of free initiator(methine S—CH integral at 7.09 ppm divided by 1) divided by the moles oftotal initiator species (moles free initiator plus molesmono-directional and bi-directional polymer chains as described above).The mole fraction of mono-directional polymeric chains was calculated bydividing the moles of mono-directional polymeric chains by the totalpolymeric chains (mono-directional and bi-directional).

The results for polymer example 11 are shown in Tables 11 and 12 below.The NMR values for conversion and Mn values were similar to the resultsdetermined gravimetrically and by GPC respectively.

TABLE 11 Gravimetric and GPC Results Irradiation time Conversion Mn MwExample (minutes) (wt %) (Da) (Da) PDI 11-1 3 2 ND ND ND 11-2 6 3 41495654 1.58 11-3 10 7 5018 7217 1.67 11-4 18 13 5828 9250 1.86 11-5 30 279524 18025 2.06 11-6 35 63 21799 35519 1.70 11-7 50 81 28024 41532 1.5611-8 70 86 31747 43971 1.47 ND: not determined

TABLE 12 NMR Results Fraction Fraction of mono- Irradiation of freedirectional time Conversion Mn initiator polymer chains Example(minutes) (mole %) (Da) (%) (%) 11-1 3 1 1724 86 100 11-2 6 2 2271 74 5111-3 10 6 3962 47 45 11-4 18 12 5439 25 46 11-5 30 26 9600 3 33 11-6 3563 22345 0 10 11-7 50 83 30630 0 4 11-8 70 99 35385 0 6

Examples 12-20

Adhesive tapes were prepared from compositions containing the materialsand amounts shown in Table 13 as follows. The compositions were preparedby mixing isooctyl acrylate (IOA, 3M Corporation, St. Paul, Minn.),acrylic acid (AA, BASF Corporation, Florham Park, N.J.), and variousphotoinitiators (PI) of the invention. The mixtures were purged withnitrogen for 5 minutes then exposed to an OSRAM SYLVANIA F40/350BLBLACKLIGHT (peak wavelength of 352 nanometers, 40 Watts) at a distanceof 10 centimeters from the lamp with mixing until a polymeric syruphaving a Brookfield viscosity of between 100 and 8000 centiPoise wasformed. To the polymeric syrup thus obtained was added2,2-dimethoxy-2-phenylacetophenone (IRGACURE 651; BASF, Corporation),hexanediol diacrylate (HDDA), and REGALREZ 6108 (RR6108, a tackifyingresin, Eastman Chemical, Kingsport, Tenn.). These were mixed for onehour to give pre-adhesive syrup compositions. These compositions werethen knife coated between a polyester film release liner and the primedsurface of 0.002 inch (51 micrometers) thick primed poly(ethyleneterephthalate) (PET) film (HOSTAPHAN 3SAB PET film, Mitsubishi PolyesterFilm, Greer, S.C.) at a thickness of 0.002 inches (51 micrometers). Thecoated compositions were irradiated for five minutes using UVA lamps(OSRAM SYLVANIA F40/350BL BLACKLIGHT, peak wavelength of 352 nanometers,40 Watts) to provide total UVA energy of 1050 milliJoules/squarecentimeter. The resulting adhesive tapes were evaluated for 180 degreeangle peel adhesion strength and shear adhesion strength as described inthe test methods.

TABLE 13 Compositions and Results Peel Adhesion Shear Strength Adhesionto SS Strength IOA AA PI RR6108 HDDA I651 oz/in to SS Ex. (grams)(grams) PI (grams) (grams) (grams) (grams) (N/dm) (minutes) 12 9.00 1.00PI-4 0.0005 — 0.015 0.015 72.7 (80.8) 10,000+ 13 9.50 0.50 PI-4 0.0005 —0.015 0.015 43.6 (48.5) 10,000+ 14 9.80 0.20 PI-4 0.0005 1.00 0.0150.015 30.6 (33.9) 10,000+ 15 9.00 1.00 PI-5 0.0005 — 0.015 0.015 71.4(79.4) 10,000+ 16 9.50 0.50 PI-5 0.0005 — 0.015 0.015 47.2 (52.5)10,000+ 17 9.80 0.20 PI-5 0.0005 1.00 0.015 0.015 27.4 (30.5) 10,000+ 189.00 1.00 PI-6 0.0005 — 0.015 0.015 69.9 (77.8) 10,000+ 19 9.50 0.50PI-6 0.0005 — 0.015 0.015 43.1 (48.0) 10,000+ 20 9.80 0.20 PI-6 0.00051.00 0.015 0.015 30.4 (33.8) 10,000+

1. A polymeric material of Formula (II)

wherein R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂; R² is alkyl,aryl, aralkyl, or substituted aryl, wherein the substituted aryl is anaryl substituted with at least one alkyl, alkoxy, halo, or a combinationthereof; each R³ is an alkyl or two adjacent R³ groups are combined withthe nitrogen to which they are both attached to form a firstheterocyclic ring having 1 to 3 heteroatoms selected from nitrogen,oxygen, and sulfur, the first heterocyclic ring being saturated orunsaturated and optionally fused to one or more second rings that arecarbocyclic or heterocyclic; P is a polymeric block comprising apolymerized product of a monomer composition comprising at least onemonomer having a single ethylenically unsaturated group; and y is aninteger in a range of 1 to 10; and z is an integer in a range of 0 to y.2. The polymeric material of claim 1, wherein the polymeric material ofFormula (II) is of Formula (II-A)

wherein group —OR¹⁰ is an alkyloxy, aralkyloxy, or alkenoxy.
 3. Thepolymeric material of claim 1, wherein the polymeric material of Formula(II) is of Formula (II-B)


4. The polymeric material of claim 1, wherein the polymeric material ofFormula (II) is of Formula (II-C)

wherein group —OR¹⁰ is an alkyloxy, aralkyloxy, or alkenoxy and groupR²⁰ is an alkyl.
 5. The polymeric material of claim 1, wherein y isequal to 1, z is equal to 1, and the polymeric material of Formula (II)is of Formula (II-1A)

wherein P¹ is a first polymeric block.
 6. The polymeric material ofclaim 1, wherein y is equal to 2, z is equal to 2, and the polymericmaterial of Formula (II) is of Formula (II-2A)

wherein P¹ is a first polymeric block and P² is a second polymericblock.
 7. A crosslinkable composition comprising: a) a polymericmaterial of Formula (II)

wherein R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂; R² is alkyl,aryl, aralkyl, or substituted aryl, wherein the substituted aryl is anaryl substituted with at least one alkyl, alkoxy, halo, or a combinationthereof; each R³ is an alkyl or two adjacent R³ groups are combined withthe nitrogen to which they are both attached to form a firstheterocyclic ring having 1 to 3 heteroatoms selected from nitrogen,oxygen, and sulfur, the first heterocyclic ring being saturated orunsaturated and optionally fused to one or more second rings that arecarbocyclic or heterocyclic; P is a polymeric block comprising apolymerized product of a monomer composition comprising at least onemonomer having a single ethylenically unsaturated group; and y is aninteger in a range of 1 to 10; and z is an integer in a range of 0 to y;and b) a second monomer composition comprising a crosslinking monomerhaving at least two ethylenically unsaturated groups.
 8. Thecrosslinkable composition of claim 7, wherein the second monomercomposition further comprises a monomer having a single ethylenicallyunsaturated group.
 9. The crosslinkable composition of claim 7, whereinthe crosslinkable composition comprises 1) 5 to 99.99 weight percentpolymeric material of Formula (II) and 2) a second monomer compositioncomprising a) 0.01 to 20 weight percent crosslinking monomer having atleast two ethylenically unsaturated groups, and b) 0 to 95 weightpercent monomer having a single ethylenically unsaturated group, whereineach amount is based on a total weight of polymerized and polymerizablematerial.
 10. The crosslinkable composition of claim 7, wherein thecrosslinkable composition further comprises a photoinitiator.
 11. Thecrosslinkable composition of claim 7, wherein the polymeric material isan elastomeric material and wherein the crosslinkable compositionfurther comprises a tackifier.
 12. A crosslinked composition comprisinga cured product of a crosslinkable composition, the crosslinkablecomposition comprising: a) a polymeric material of Formula (II)

wherein R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂; R² is alkyl,aryl, aralkyl, or substituted aryl, wherein the substituted aryl is anaryl substituted with at least one alkyl, alkoxy, halo, or a combinationthereof; each R³ is an alkyl or two adjacent R³ groups are combined withthe nitrogen to which they are both attached to form a firstheterocyclic ring having 1 to 3 heteroatoms selected from nitrogen,oxygen, and sulfur, the first heterocyclic ring being saturated orunsaturated and optionally fused to one or more second rings that arecarbocyclic or heterocyclic; P is a polymeric block comprising apolymerized product of a monomer composition comprising at least onemonomer having a single ethylenically unsaturated group; and y is aninteger in a range of 1 to 10; and z is an integer in a range of 0 to y;and b) a second monomer composition comprising a crosslinking monomerhaving at least two ethylenically unsaturated groups.
 13. An articlecomprising a first substrate and a crosslinked composition layeradjacent to the first substrate, wherein the crosslinked compositionlayer comprises the crosslinked composition of claim
 12. 14. A firstreaction mixture comprising: a) an initiator compound of Formula (I)

wherein R¹ is an alkoxy, aralkyloxy, alkenoxy or —N(R³)₂; R² is alkyl,aryl, aralkyl, or substituted aryl, wherein the substituted aryl is anaryl substituted with at least one alkyl, alkoxy, halo, or a combinationthereof; and each R³ is an alkyl or two adjacent R³ groups are combinedwith the nitrogen to which they are both attached to form a firstheterocyclic ring having 1 to 3 heteroatoms selected from nitrogen,oxygen, and sulfur, the first heterocyclic ring being saturated orunsaturated and optionally fused to one or more second rings that arecarbocyclic or heterocyclic; and b) a monomer composition 1A containingat least one monomer having a single ethylenically unsaturated group.15. A compound of Formula (I-B)

wherein R² is aryl, aralkyl, or substituted aryl, wherein thesubstituted aryl is an aryl substituted with at least one alkyl, alkoxy,halo, or combination thereof; and each R³ is an alkyl or two adjacent R³groups are combined with the nitrogen to which they are both attached toform a first heterocyclic ring having 1 to 3 heteroatoms selected fromnitrogen, oxygen, and sulfur, the first heterocyclic ring beingsaturated or unsaturated and optionally fused to one or more secondrings that are carbocyclic or heterocyclic.
 16. A compound of Formula(I-C)

wherein group —OR¹⁰ is an alkoxy, aralkyloxy, or alkenoxy; and group R²⁰is an alkyl.